How to create the store package (appxbundle) in Winui by using Command prompt or powershell

[sudharsan-narayanan]

How to create the store package (appxbundle) for WinUI project by using Command prompt or PowerShell command.

Without using the visual studio for creating the package.

[DarranRowe]

The first thing to point out is that you are generally going to be working towards making a .msixbundle file. The store does accept submissions with the .msix, .msixbundle and .msixupload extensions.
The command line method for creating the packages and bundles is documented. If you want to then also make the .msixupload file, then the contents is also documented.
For a more concrete example of this. Suppose I have used Visual Studio to make all of my .msix files, and I want to create the store submission from this.

The .msix files have been copied to a directory under D:\Packaging.

makeappx bundle /v /d D:\packaging\packages /bv 1.0.0.0 /p "D:\packaging\bundle\Meh (Package)_1.0.0.0_x86_x64_ARM64.msixbundle"
signtool sign /fd SHA256 /a /sha1 <signing certificate hash> "D:\packaging\bundle\Meh (Package)_1.0.0.0_x86_x64_ARM64.msixbundle"

The makeappx command creates the .msixbundle file. You must then sign it with your code signing certificate if you wish to be able to side load the package. I use signtool specifying an already installed certificate for this. But any method of signing the bundle will work. This .msixbundle should be uploadable to the store as is, but creating the upload file, which includes the debug symbols, is recommended.

From here, to create the .msixupload file requires some means of creating .zip files. You should also include the debug symbols for your project, including all architectures that was added to the bundle. These should be in a file with a .appxsym extension. If Visual Studio already created these, use those.

If not, you will want to find all of your .pdb files.

Remember, these are specific to your executable and library files, so you will need to separate them out. This also means that the .appxsym file would need to be recreated if you rebuild the project. As a side note, since these remaining files are all renamed .zip files, you can just use explorer to create a .zip file and copy everything needed into each file. You would then need to change the extension.
Anyway, to create this on the command line, I set up the directory so that it splits the .pdb files by platform.

Each platform directory contains the .pdb files for that platform. As a side note, only .pdb files that are generated from your build should be included here.

With this layout, I can use some command line tool to generate the .zip file. Powershell also has the Compress-Archive cmdlet. If I use 7-zip to generate the .zip files:

7z a "D:\packaging\symbols\Meh (Package)_1.0.0.0_ARM64.zip" D:\packaging\symbolcache\ARM64\*
7z a "D:\packaging\symbols\Meh (Package)_1.0.0.0_x64.zip" D:\packaging\symbolcache\x64\*
7z a "D:\packaging\symbols\Meh (Package)_1.0.0.0_x86.zip" D:\packaging\symbolcache\x86\*
ren "D:\packaging\symbols\Meh (Package)_1.0.0.0_ARM64.zip" "Meh (Package)_1.0.0.0_ARM64.appxsym"
ren "D:\packaging\symbols\Meh (Package)_1.0.0.0_x64.zip" "Meh (Package)_1.0.0.0_x64.appxsym"
ren "D:\packaging\symbols\Meh (Package)_1.0.0.0_x86.zip" "Meh (Package)_1.0.0.0_x86.appxsym"

Finally, from the layout shown in screenshots above, you can finally create the .msixupload file from the bundle and symbols.

7z a "D:\packaging\Meh (Package)_1.0.0.0.zip" D:\packaging\bundle\* D:\packaging\symbols\*
ren "D:\packaging\Meh (Package)_1.0.0.0.zip" "Meh (Package)_1.0.0.0.msixupload"

[sudharsan-narayanan]

Thanks for the answer, but I need a command to create a package via the command prompt for the WinUI project. So, anyone can help by sharing a command to create a package. If it is a video or code snippet, it is better for us.

[ghost1372]

download this target file and import into your csproj file
https://gist.githubusercontent.com/mattleibow/8332ed79b569c9d7bbdae64a6e8142a6/raw/ff97af7ddd59698274e1879b5222dc403c5712a8/Microsoft.Build.Msix.Packaging.MsixBundle.targets

and now you can create msixbundle with visual studio wizard

[sudharsan-narayanan]

Thanks for the answer, but I need a command to create a package via the command prompt for the WinUI project. So, anyone can help by sharing a command to create a package. If it is a video or code snippet, it is better for us.

[DarranRowe]

I honestly skipped over the package creation for two reasons. First the documentation that I linked to gives a very good overview of packaging applications from the command line. Second, Visual Studio with diagnostic logging will log all of the command lines used as well as all of the artefacts required will be available.

I have no issues putting together more of a step by step guide, but it is certainly not going to be a single command.

[DarranRowe]

Now for a little step by step guide on how to take the output of the build process and package it on the command line.
As a major disclaimer, I obtained most of these steps by using the Blank App, Packaged with Windows Application Packaging Project (WinUI 3 in Desktop) template.

I save the log from the Publish option.

I also heavily referenced the intermediate build output for both the application and the packaging process.

So, to make a disclaimer immediately, this general process should work for any application type. It is up to you to figure out the layout of the package, what files you want in the resources.pri file and how the package itself is supposed to be set up. Because each application is different, I can only provide general instructions.

I will be working towards bundling up a WinUI 3 project for 3 platforms. It is an executable with a WinRT component. The build output itself will be coming from a C++ WinUI 3 project. The only configuration change I made is that I added <WindowsPackageType>None</WindowsPackageType> and <WindowsAppSDKBootstrapAutoInitializeOptions_OnPackageIdentity_NoOp>true</WindowsAppSDKBootstrapAutoInitializeOptions_OnPackageIdentity_NoOp> to the executable project file. This is so I am able to test the application prior to packaging it up.

So, step 1 is to build your project and make sure that it is in a ready to run configuration. How you do this is outside of the scope of this guide, but if you are working with a C# project then you really should make the C# runtime self contained. You do not have to make the Windows App SDK self contained though.

Step 2. Set up the packaging directory. I had it configured so that it was per platform.

If you only want to make a single platform .msix package, then you don't have to do this. But when you are working towards uploading to the store, then this kind of layout is useful.

Step 3. Copy the required build output to the packaging directory.

This is for x64, the same files are copied for x86 and ARM64 from the relevant build output directories. The presence of Microsoft.WindowsAppRuntime.Bootstrap.dll is only for testing purposes. This will not be part of the package. Importantly, I have not copied any of the .xbf files here.
The reason is that for the Release configuration, Visual Studio embeds the .xbf files into the .pri files. Since this first portion of this step by step guide is to take the build output from Visual Studio and produce a .msix file, then I won't show what happens when the .xbf files are not embedded. I will properly show the layout without embedding at a later time.
If you want to know if Visual Studio has embedded any files, look at the intermediate build output.

You can see that the embed.resfiles is not 0 in size. This means that the files named in embedded.resfiles will be embedded into the .pri file. If you ever want to know the contents of a .pri file, makepri has a dump command. So, to look at the contents of the TestBundle.pri file above, I can use the command:

C:\Users\Darran\manual\TestBundle\x64>makepri dump /if TestBundle.pri /of TestBundle.pri.xml

This will place the contents of the .pri file into a readable xml file. The output of the above is:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<PriInfo>
	<ResourceMap name="TestBundle" version="1.0" primary="true">
		<Qualifiers>
			<Language>EN-GB,JA-JP</Language>
		</Qualifiers>
		<ResourceMapSubtree name="Files">
			<NamedResource name="App.xbf" uri="ms-resource://TestBundle/Files/App.xbf">
				<Candidate type="EmbeddedData">
					<Base64Value>[Embedded Binary Data]</Base64Value>
				</Candidate>
			</NamedResource>
			<NamedResource name="MainWindow.xbf" uri="ms-resource://TestBundle/Files/MainWindow.xbf">
				<Candidate type="EmbeddedData">
					<Base64Value>[Embedded Binary Data]</Base64Value>
				</Candidate>
			</NamedResource>
			<ResourceMapSubtree name="TestComponent">
				<NamedResource name="TestPage.xbf" uri="ms-resource://TestBundle/Files/TestComponent/TestPage.xbf">
					<Candidate type="EmbeddedData">
						<Base64Value>[Embedded Binary Data]</Base64Value>
					</Candidate>
				</NamedResource>
			</ResourceMapSubtree>
		</ResourceMapSubtree>
		<ResourceMapSubtree name="Strings">
			<NamedResource name="Greeting" uri="ms-resource://TestBundle/Strings/Greeting">
				<Candidate qualifiers="Language-JA-JP" type="String">
					<Value>こんにちは</Value>
				</Candidate>
				<Candidate qualifiers="Language-EN-GB" isDefault="true" type="String">
					<Value>Hello</Value>
				</Candidate>
			</NamedResource>
		</ResourceMapSubtree>
		<ResourceMapSubtree name="TestComponent">
			<ResourceMapSubtree name="Strings">
				<NamedResource name="Test" uri="ms-resource://TestBundle/TestComponent/Strings/Test">
					<Candidate qualifiers="Language-JA-JP" type="String">
						<Value>テスト</Value>
					</Candidate>
					<Candidate qualifiers="Language-EN-GB" isDefault="true" type="String">
						<Value>Test</Value>
					</Candidate>
				</NamedResource>
			</ResourceMapSubtree>
		</ResourceMapSubtree>
	</ResourceMap>
</PriInfo>

As you can see, App.xbf, MainWindow.xbf and TestPage.xbf are all marked clearly as embedded. TestPage.xbf comes from TestComponent, so the other important points that you can see from this are that the resources for TestComponent must also be in the main resources.pri (or executable's .pri file for unpackaged applications), and they must also be under a subtree with a name that matches the component. If the files are not marked as embedded, then you must copy them to the correct package locations too. More on this later.

Step 4. Generate resources.pri.

The package resources.pri file must also contain the resources for the package, not just the application. So any images that you use in the AppxManifest.xml file must be in indexed in resources.pri. To start this off, I configure the packaging artefact directory as follows:

The package images are in the Image directory. The base resources don't need to be per platform, I keep doing it this way because that is how Visual Studio does it and without a script to generate these files on the fly, it is easier to keep things per platform. I create 5 files and one directory. These files are priconfig.xml, filtered.layout.resfiles, pri.resfiles, resources.resfiles and embed.resfiles. Again, these names are not required, I just used them due to Visual Studio doing the same. The contents of priconfig.xml is:

<?xml version="1.0" encoding="utf-8"?>
<resources targetOsVersion="10.0.0" majorVersion="1">
  <index root="\" startIndexAt="x64\filtered.layout.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="\" startIndexAt="x64\resources.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESW" convertDotsToSlashes="true" />
    <indexer-config type="RESJSON" />
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="\" startIndexAt="x64\pri.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="PRI" />
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="x64\embed" startIndexAt="embed.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESFILES" qualifierDelimiter="." />
    <indexer-config type="EMBEDFILES" />
  </index>
</resources>

Since I am using the output of a Visual Studio build with the fully generated .pri files, I don't need the resources.resfiles and embed.resfiles sections. However, this is how Visual Studio generates it and I think it is a nice template. The big things to note is that the Language is set to en-GB here, this is the default language that I set. This would change depending on the default language you want in your application package. The Scale is the default DPI scaling that is chosen by Visual Studio, you can again change this. You can configure this as you want, this file uses the same format as the UWP resource management system. So you can use that documentation as reference.

Both resources.resfiles and embed.resfiles are empty here. For the remaining files, pri.resfiles contains the absolute path to the .pri files generated by Visual Studio.

C:\Users\Darran\manual\TestBundle\x64\TestComponent.pri
C:\Users\Darran\manual\TestBundle\x64\TestBundle.pri

You can see that the path contains a platform identifier, but these .pri files should be the same regardless of platform. So if you are feeling adventurous, then maybe you can slim this down a little. Finally, filtered.layout.resfiles contains the relative path to the package image files. The directory that it is using as the base directory is given in the makepri command line. The contents is:

Images\BadgeLogo.scale-100.png
Images\BadgeLogo.scale-125.png
Images\BadgeLogo.scale-150.png
Images\BadgeLogo.scale-200.png
Images\BadgeLogo.scale-400.png
Images\LargeTile.scale-100.png
Images\LargeTile.scale-125.png
Images\LargeTile.scale-150.png
Images\LargeTile.scale-200.png
Images\LargeTile.scale-400.png
Images\LockScreenLogo.scale-100.png
... more

The contents matches the contents of the Images directory in the package artefacts directory. With these files in place it is time to run makepri. The command that I used is:

C:\Users\Darran\manual\TestBundle\PackageArtefacts>makepri new -projectroot C:\Users\Darran\manual\TestBundle\PackageArtefacts -configxml C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\priconfig.xml -outputfile C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\resources\resources.pri -indexname Untrusted.TestBundle -verbose -overwrite

The -ProjectRoot option tells makepri what directory to use as the base directory for any relative lookups. So when it looks in the priconfig.xml and finds <index root="\" startIndexAt="x64\filtered.layout.resfiles">, makepri will start in this project root directory and look for a relative path of x64\filtered.layout.resfiles. The -IndexName option changes the root index of the resources.pri file to match the package identity that will be given in the AppxManifest.xml file. Again, this name is completely up to you.

Step 5. Generate the package file.

First of all, I am creating the package using a mapping file. This isn't the only way of doing this. I prefer using the mapping file since it gives more flexibility. The mapping file contains the types of resources available as well as the files in the package. The files are a pair of paths, the absolute path name of the existing file and the relative path to the file in the package. This file will be named main.map.txt and will be placed in the platform specific package artefact directory. C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\main.map.txt

[ResourceMetadata]
"ResourceDimensions"		"scale-100"
"ResourceDimensions"		"scale-125"
"ResourceDimensions"		"scale-150"
"ResourceDimensions"		"scale-200"
"ResourceDimensions"		"scale-400"
"ResourceDimensions"		"language-en-gb"
"ResourceDimensions"		"language-ja-jp"

[Files]
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\resources\resources.pri"		"resources.pri"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\BadgeLogo.scale-100.png"		"Images\BadgeLogo.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\BadgeLogo.scale-125.png"		"Images\BadgeLogo.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\BadgeLogo.scale-150.png"		"Images\BadgeLogo.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\BadgeLogo.scale-200.png"		"Images\BadgeLogo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\BadgeLogo.scale-400.png"		"Images\BadgeLogo.scale-400.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LargeTile.scale-100.png"		"Images\LargeTile.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LargeTile.scale-125.png"		"Images\LargeTile.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LargeTile.scale-150.png"		"Images\LargeTile.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LargeTile.scale-200.png"		"Images\LargeTile.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LargeTile.scale-400.png"		"Images\LargeTile.scale-400.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LockScreenLogo.scale-100.png"			"Images\LockScreenLogo.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LockScreenLogo.scale-125.png"			"Images\LockScreenLogo.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LockScreenLogo.scale-150.png"			"Images\LockScreenLogo.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LockScreenLogo.scale-200.png"			"Images\LockScreenLogo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LockScreenLogo.scale-400.png"			"Images\LockScreenLogo.scale-400.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SmallTile.scale-100.png"		"Images\SmallTile.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SmallTile.scale-125.png"		"Images\SmallTile.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SmallTile.scale-150.png"		"Images\SmallTile.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SmallTile.scale-200.png"		"Images\SmallTile.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SmallTile.scale-400.png"		"Images\SmallTile.scale-400.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SplashScreen.scale-100.png"			"Images\SplashScreen.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SplashScreen.scale-125.png"			"Images\SplashScreen.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SplashScreen.scale-150.png"			"Images\SplashScreen.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SplashScreen.scale-200.png"			"Images\SplashScreen.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SplashScreen.scale-400.png"			"Images\SplashScreen.scale-400.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square150x150Logo.scale-100.png"			"Images\Square150x150Logo.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square150x150Logo.scale-125.png"			"Images\Square150x150Logo.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square150x150Logo.scale-150.png"			"Images\Square150x150Logo.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square150x150Logo.scale-200.png"			"Images\Square150x150Logo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square150x150Logo.scale-400.png"			"Images\Square150x150Logo.scale-400.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-16.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-16.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-24.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-24.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-256.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-256.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-32.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-32.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-48.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-48.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-16.png"			"Images\Square44x44Logo.altform-unplated_targetsize-16.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-24.png"			"Images\Square44x44Logo.altform-unplated_targetsize-24.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-256.png"			"Images\Square44x44Logo.altform-unplated_targetsize-256.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-32.png"			"Images\Square44x44Logo.altform-unplated_targetsize-32.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-48.png"			"Images\Square44x44Logo.altform-unplated_targetsize-48.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.scale-100.png"			"Images\Square44x44Logo.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.scale-125.png"			"Images\Square44x44Logo.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.scale-150.png"			"Images\Square44x44Logo.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.scale-200.png"			"Images\Square44x44Logo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.scale-400.png"			"Images\Square44x44Logo.scale-400.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-16.png"			"Images\Square44x44Logo.targetsize-16.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-24.png"			"Images\Square44x44Logo.targetsize-24.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-256.png"			"Images\Square44x44Logo.targetsize-256.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-32.png"			"Images\Square44x44Logo.targetsize-32.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-48.png"			"Images\Square44x44Logo.targetsize-48.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\StoreLogo.scale-100.png"			"Images\StoreLogo.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\StoreLogo.scale-125.png"			"Images\StoreLogo.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\StoreLogo.scale-150.png"			"Images\StoreLogo.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\StoreLogo.scale-200.png"			"Images\StoreLogo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\StoreLogo.scale-400.png"			"Images\StoreLogo.scale-400.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Wide310x150Logo.scale-100.png"			"Images\Wide310x150Logo.scale-100.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Wide310x150Logo.scale-125.png"			"Images\Wide310x150Logo.scale-125.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Wide310x150Logo.scale-150.png"			"Images\Wide310x150Logo.scale-150.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Wide310x150Logo.scale-200.png"			"Images\Wide310x150Logo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Wide310x150Logo.scale-400.png"			"Images\Wide310x150Logo.scale-400.png"
"C:\Users\Darran\manual\TestBundle\x64\TestBundle.exe"			"TestBundle.exe"
"C:\Users\Darran\manual\TestBundle\x64\TestBundle.pri"			"TestBundle.pri"
"C:\Users\Darran\manual\TestBundle\x64\TestBundle.winmd"			"TestBundle.winmd"
"C:\Users\Darran\manual\TestBundle\x64\TestComponent.dll"			"TestComponent.dll"
"C:\Users\Darran\manual\TestBundle\x64\TestComponent.pri"			"TestComponent.pri"
"C:\Users\Darran\manual\TestBundle\x64\TestComponent.winmd"			"TestComponent.winmd"

I then create the AppxManifest.xml file. This is also placed in the platform specific package artefact directory. C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\AppxManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<Package xmlns="http://schemas.microsoft.com/appx/manifest/foundation/windows10" xmlns:mp="http://schemas.microsoft.com/appx/2014/phone/manifest" xmlns:uap="http://schemas.microsoft.com/appx/manifest/uap/windows10" xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities" IgnorableNamespaces="uap rescap">
  <Identity Name="Untrusted.TestBundle" Publisher="<Make this match your signing certificate>" Version="1.0.0.0" ProcessorArchitecture="x64" />
  <mp:PhoneIdentity PhoneProductId="<Generate a new GUID for your application>" PhonePublisherId="00000000-0000-0000-0000-000000000000" />
  <Properties>
    <DisplayName>TestBundle</DisplayName>
    <PublisherDisplayName>Darran</PublisherDisplayName>
    <Logo>Images\StoreLogo.png</Logo>
  </Properties>
  <Dependencies>
    <TargetDeviceFamily Name="Windows.Universal" MinVersion="10.0.17763.0" MaxVersionTested="10.0.22621.0" />
    <TargetDeviceFamily Name="Windows.Desktop" MinVersion="10.0.17763.0" MaxVersionTested="10.0.22621.0" />
    <PackageDependency Name="Microsoft.WindowsAppRuntime.1.4" MinVersion="4000.1049.117.0" Publisher="CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" />
    <PackageDependency Name="Microsoft.VCLibs.140.00" MinVersion="14.0.30704.0" Publisher="CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" />
    <PackageDependency Name="Microsoft.VCLibs.140.00.UWPDesktop" MinVersion="14.0.30704.0" Publisher="CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" />
  </Dependencies>
  <Resources>
    <Resource Language="EN-GB" />
  </Resources>
  <Applications>
    <Application Id="App" Executable="TestBundle.exe" EntryPoint="Windows.FullTrustApplication">
      <uap:VisualElements DisplayName="TestBundle" Description="TestBundle" BackgroundColor="transparent" Square150x150Logo="Images\Square150x150Logo.png" Square44x44Logo="Images\Square44x44Logo.png">
        <uap:DefaultTile Wide310x150Logo="Images\Wide310x150Logo.png" Square71x71Logo="Images\SmallTile.png" Square310x310Logo="Images\LargeTile.png">
          <uap:ShowNameOnTiles>
            <uap:ShowOn Tile="square310x310Logo" />
          </uap:ShowNameOnTiles>
        </uap:DefaultTile>
        <uap:SplashScreen Image="Images\SplashScreen.png" />
        <uap:LockScreen BadgeLogo="Images\BadgeLogo.png" Notification="badge" />
      </uap:VisualElements>
    </Application>
  </Applications>
  <Capabilities>
    <rescap:Capability Name="runFullTrust" />
  </Capabilities>
  <Extensions>
    <Extension Category="windows.activatableClass.inProcessServer">
      <InProcessServer>
        <Path>TestComponent.dll</Path>
        <ActivatableClass ActivatableClassId="TestComponent.TestPage" ThreadingModel="both" />
        <ActivatableClass ActivatableClassId="TestComponent.XamlMetaDataProvider" ThreadingModel="both" />
        <ActivatableClass ActivatableClassId="TestComponent.Class" ThreadingModel="both" />
      </InProcessServer>
    </Extension>
  </Extensions>
</Package>

It should go without saying that this file is very customised to my application. In general, you need to fill out the identity, phone identity, properties and applications elements to match your package. I cannot give you information on how to fill this out. This manifest also has an Extensions section due to the WinRT component, this provides activation information for the package, but again, this is something that is needed due to my package layout. This also uses the pre Windows 10 2004/20H1 method of stating that the application is a packaged windows desktop application that runs at medium IL. Again, this will change depending on your application. You really need to reference the manifest schema to figure out how to fill in your AppxManifest.xml file. With the file map and the AppxManifest.xml file completed, you will then run makeappx:

C:\Users\Darran\manual\TestBundle\PackageArtefacts>makeappx pack /l /h sha256 /m C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\AppxManifest.xml /f C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\main.map.txt /o /p C:\Users\Darran\manual\TestBundle\Packages\TestBundle_1.0.0.0_x64.msix

Finally, sign the package with your certificate, if necessary.

C:\Users\Darran\manual\TestBundle\PackageArtefacts>signtool sign /fd SHA256 /a /sha1 <signing certificate hash> C:\Users\Darran\manual\TestBundle\Packages\TestBundle_1.0.0.0_x64.msix

Again, the certificate is your code signing certificate. I used a certificate that is in my user's certificate store, so I was able to reference it by the hash alone here. This step is needed if you want to side load the application.

You can use the same instructions to generate the packages for the other platforms. Obviously substituting platform paths and any other processor specific values. Once you have all packages created then you can bundle them up.

But wait, these do not have the split resources. Because of how long this post is, I will cover the remaining topics in a separate post. As a major note, while this is packaging up a project that is built for WinUI 3, these manual packaging steps are completely technology agnostic. If you are targetting WinUI 2 in a UWP application or using WinUI in a Xaml Islands desktop application, these steps will also work. You just need to modify the resources.pri, file map and AppxManifest.xml accordingly.

[DarranRowe]

Right, to clean up some of the remaining topics.

What happens if the .xbf files are not embedded?

You can identify this in two ways. First, if you look at the embed.resfiles file, it will have a 0 byte size.

The other way to identify this is if you dump the .pri file that you are working with.

C:\Users\Darran\source\repos\TestBundle\x64\Debug\TestBundle>makepri dump /if TestBundle.pri /of TestBundle.pri.xml

Yes, I am working with the debug version of the same application here. The debug builds never embed the .xbf files by default. The output .xml file contains:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<PriInfo>
	<ResourceMap name="TestBundle" version="1.0" primary="true">
		<Qualifiers>
			<Language>EN-GB,JA-JP</Language>
		</Qualifiers>
		<ResourceMapSubtree name="Files">
			<NamedResource name="App.xbf" uri="ms-resource://TestBundle/Files/App.xbf">
				<Candidate type="Path">
					<Value>App.xbf</Value>
				</Candidate>
			</NamedResource>
			<NamedResource name="MainWindow.xbf" uri="ms-resource://TestBundle/Files/MainWindow.xbf">
				<Candidate type="Path">
					<Value>MainWindow.xbf</Value>
				</Candidate>
			</NamedResource>
			<ResourceMapSubtree name="TestComponent">
				<NamedResource name="TestPage.xbf" uri="ms-resource://TestBundle/Files/TestComponent/TestPage.xbf">
					<Candidate type="Path">
						<Value>TestComponent\TestPage.xbf</Value>
					</Candidate>
				</NamedResource>
			</ResourceMapSubtree>
		</ResourceMapSubtree>
		<ResourceMapSubtree name="Strings">
			<NamedResource name="Greeting" uri="ms-resource://TestBundle/Strings/Greeting">
				<Candidate qualifiers="Language-JA-JP" type="String">
					<Value>こんにちは</Value>
				</Candidate>
				<Candidate qualifiers="Language-EN-GB" isDefault="true" type="String">
					<Value>Hello</Value>
				</Candidate>
			</NamedResource>
		</ResourceMapSubtree>
		<ResourceMapSubtree name="TestComponent">
			<ResourceMapSubtree name="Strings">
				<NamedResource name="Test" uri="ms-resource://TestBundle/TestComponent/Strings/Test">
					<Candidate qualifiers="Language-JA-JP" type="String">
						<Value>テスト</Value>
					</Candidate>
					<Candidate qualifiers="Language-EN-GB" isDefault="true" type="String">
						<Value>Test</Value>
					</Candidate>
				</NamedResource>
			</ResourceMapSubtree>
		</ResourceMapSubtree>
	</ResourceMap>
</PriInfo>

As you can see, the .xbf files now have a Candidate element with the type attribute stating Path. This means that when the application looks for the resource, it will look at the specified path relative to the resources.pri file or the application executable. This means that you will have to place the files in the correct location specified by the .pri file.

If you deploy this kind of project with Visual Studio then it will place the files in the correct location.

There are a couple of extra files, but the layout is correct. For extra information, Microsoft.WindowsAppRuntime.Bootstrap.dll and TestPage.xaml are not useful here.

TestPage.xaml is in the wrong place to even be useful, and the component will use TestPage.xbf under the TestComponent sub directory. Microsoft.WindowsAppRuntime.Bootstrap.dll will never be used by a packaged application. The Windows App Runtime reference is resolved by the AppxManifest file.

These files would then have to be added to the file map too, if you are using the file map.

Are you trying to package up an application built using the debug configuration?

The biggest difference here is that you want to reference any debug libraries if it matters. The dependencies of a package built using the debug configuration could be:

  <Dependencies>
    <TargetDeviceFamily Name="Windows.Universal" MinVersion="10.0.17763.0" MaxVersionTested="10.0.22621.0" />
    <TargetDeviceFamily Name="Windows.Desktop" MinVersion="10.0.17763.0" MaxVersionTested="10.0.22621.0" />
    <PackageDependency Name="Microsoft.WindowsAppRuntime.1.4" MinVersion="4000.1049.117.0" Publisher="CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" />
    <PackageDependency Name="Microsoft.VCLibs.140.00.Debug" MinVersion="14.0.30704.0" Publisher="CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" />
    <PackageDependency Name="Microsoft.VCLibs.140.00.Debug.UWPDesktop" MinVersion="14.0.30704.0" Publisher="CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" />
  </Dependencies>

As you can see, this references the debug versions of the VC libraries. It is important to note that the debug versions of these libraries also contain the release versions.

One final thing, if your application built using the debug configuration uses the CRT, or uses any component that uses the CRT, then you will have to place urctbased.dll into your package too. You should place this in your application's layout directory and also reference it in your file map if you are using the file map.
Just remember that the debug runtimes are not classed as redistributable. This means that you should limit distribution of any packages which use the debug runtimes to people debugging the application only.

Are you using some kind of build system that doesn't generate some or all of the .pri files?

Any resources used need to be in the package's resources.pri file. This means, if you don't have any or some of the .pri files generated by Visual Studio, then you will have to fill in the gaps yourself. The makepri usage doesn't change too much, you just need to reference the individual resources instead of the output .pri files. The strings in my application and components get copied to the package artefacts directory.
This example shows how to generate the complete resources.pri file.

The layout is important, since the path relative to the root specified in the priconfig.xml determines the resource path in the .pri file. The TestComponent Strings directory also contains the language identifiers, and each of these directories contain a file named Strings.resw. I also copy all of the .xbf files to the platform specific directories. Again, this shouldn't matter, but Visual Studio keeps these separate.

If the .xbf files are not going to be embedded into the .pri file, then the priconfig.xml file will need to add a separate section to add the platform specific files. The section for the strings from TestComponent will also need to have the TestComponent prefix added. The updated priconfig.xml file will look like:

<?xml version="1.0" encoding="utf-8"?>
<resources targetOsVersion="10.0.0" majorVersion="1">
  <index root="\" startIndexAt="x64\filtered.layout.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="x64" startIndexAt="filtered.layout.platform.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="\" startIndexAt="x64\resources.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESW" convertDotsToSlashes="true" />
    <indexer-config type="RESJSON" />
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="\" startIndexAt="x64\resources.testcomponent.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESW" convertDotsToSlashes="true" initialPath="TestComponent" />
    <indexer-config type="RESJSON" />
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="\" startIndexAt="x64\pri.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="PRI" />
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="x64\embed" startIndexAt="embed.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESFILES" qualifierDelimiter="." />
    <indexer-config type="EMBEDFILES" />
  </index>
</resources>

I copied the filtered.layout.resfiles section and changed the root to the x64 directory here. The filtered.layout.platform.resfiles contains:

App.xbf
MainWindow.xbf
TestComponent\TestPage.xbf

This change in path is important because it determines the relative path to the root of the package. These files couldn't be placed on the end of filtered.layout.resfiles, where all of the images are, because they would all have the x64 portion of the path in the .pri file. You could take advantage of the fact that all .xbf files should be the same and place them in the project root. That way you could add them to the end of the filtered.layout.resfiles.
The file pri.resfiles is now empty, since I am not referencing any .pri files.
The file embed.resfiles is again empty.
The file resources.resfiles now contains the string resources for the main application. This file now contains:

C:\Users\Darran\manual\TestBundle\PackageArtefacts\Strings\en-GB\Strings.resw
C:\Users\Darran\manual\TestBundle\PackageArtefacts\Strings\ja-JP\Strings.resw

Finally, I added the resources.testcomponent.resfiles file and this file contains the string resources for the component. The initialPath attribute is used to add the required prefix to the path. This file contains:

C:\Users\Darran\manual\TestBundle\PackageArtefacts\TestComponent\Strings\en-GB\Strings.resw
C:\Users\Darran\manual\TestBundle\PackageArtefacts\TestComponent\Strings\ja-JP\Strings.resw

Interestingly, because the priconfig.xml specifies everything needed, the command line for makepri is the same as before.
If you wish to embed the .xbf files, then you have to add the .xbf files to embed.resfiles instead of having them in the filtered.layout.platform.resfiles section. The priconfig.xml file would thus be:

<?xml version="1.0" encoding="utf-8"?>
<resources targetOsVersion="10.0.0" majorVersion="1">
  <index root="\" startIndexAt="x64\filtered.layout.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="\" startIndexAt="x64\resources.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESW" convertDotsToSlashes="true" />
    <indexer-config type="RESJSON" />
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="\" startIndexAt="x64\resources.testcomponent.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESW" convertDotsToSlashes="true" initialPath="TestComponent" />
    <indexer-config type="RESJSON" />
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="\" startIndexAt="x64\pri.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="PRI" />
    <indexer-config type="RESFILES" qualifierDelimiter="." />
  </index>
  <index root="x64\embed" startIndexAt="embed.resfiles">
    <default>
      <qualifier name="Language" value="en-GB" />
      <qualifier name="Contrast" value="standard" />
      <qualifier name="Scale" value="200" />
      <qualifier name="HomeRegion" value="001" />
      <qualifier name="TargetSize" value="256" />
      <qualifier name="LayoutDirection" value="LTR" />
      <qualifier name="DXFeatureLevel" value="DX9" />
      <qualifier name="Configuration" value="" />
      <qualifier name="AlternateForm" value="" />
      <qualifier name="Platform" value="UAP" />
    </default>
    <indexer-config type="RESFILES" qualifierDelimiter="." />
    <indexer-config type="EMBEDFILES" />
  </index>
</resources>

There wouldn't be a filtered.layout.platform.resfiles in this layout. Instead, the .xbf files would be copied to the embed directory:

The TestComponent directory has to exist to place TestPage.xbf in the correct path in the .pri file. Then embed.resfiles would be modified to contain:

App.xbf
MainWindow.xbf
TestComponent\TestPage.xbf

This generates the complete resources.pri from just the resources. If you have some component .pri files, TestComponent.pri as an example, then you can just reference those using pri.resfiles and not add the individual files.
If you are ever in the position where you don't know the exact path to the resources, just dump the .pri file. The value of the Path type entries will always give you the relative path of the resource to the resources.pri file. Dumping the contents of the resources.pri file is also useful to verify that the file is correct.

Do you want to create a package with a .appx extension?

These steps provided have all output packages with .msix extensions. However, as you may have noticed, I have created an AppxManifest.xml file and used makeappx.exe to generate these packages. The MSIX overview also provides information on what is inside an MSIX package, which includes files that start with Appx.
MSIX can be seen as a rebranding of Appx. The supported platforms for MSIX give Windows 10 1709 as the earliest supported version. As a convention, I believe that Visual Studio looks at the TargetDeviceFamily entries in the AppxManifest.xml file and looks at the MinVersion entries. If any one of these specifies a version lower that Windows 10 1709 (10.0.16299.0), or maybe it is one of the pre-release versions for this version of Windows 10, then it will give the package a .appx extension. Otherwise it will give the package a .msix extension.
This means that you should treat .appx and .msix as equivalent. If you need the .appx extension, just change the extension given in the /p parameter for makeappx. The same is true for the equivalence between .appxbundle and .msixbundle and .appxupload and .msixupload.

[DarranRowe]

Finally there are the split resources.

I would say that there are generally four steps to this.

Step 1. Generate resources.pri. By now, you should be able to generate this file, so I'll just move on.

Step 2. Generate split.priconfig.xml and the split resources.
This file gives the resources that should be kept in the main .pri file. It will then generate separate .pri files for each of the other resources. The contents of split.priconfig.xml I am using is:

<?xml version="1.0" encoding="utf-8"?>
<resources targetOsVersion="10.0.0" majorVersion="1">
	<packaging>
		<autoResourcePackage qualifier="Language" />
		<autoResourcePackage qualifier="Scale" />
		<autoResourcePackage qualifier="DXFeatureLevel" />
		<omitSchemaFromResourcePacks />
	</packaging>
	<index root="\" startIndexAt="x64\resources\resources.pri">
		<default>
			<qualifier name="Language" value="en-GB" />
			<qualifier name="Contrast" value="standard" />
			<qualifier name="Scale" value="200" />
			<qualifier name="HomeRegion" value="001" />
			<qualifier name="TargetSize" value="256" />
			<qualifier name="LayoutDirection" value="LTR" />
			<qualifier name="DXFeatureLevel" value="DX9" />
			<qualifier name="Configuration" value="" />
			<qualifier name="AlternateForm" value="" />
			<qualifier name="Platform" value="UAP" />
		</default>
		<indexer-config type="PRI" />
	</index>
</resources>

An important point to make at this point is that if you are using this kind of layout. It is expected that all split resources will be the same for different platforms. For example, the images for the x86, x64 and ARM64 platforms should be the same. Visual Studio itself only creates the split resources from the last platform it packages. I will only be using the resources for x64 to create the split packages.
I use the following makepri command line:

C:\Users\Darran\manual\TestBundle\PackageArtefacts>makepri new -projectroot C:\Users\Darran\manual\TestBundle\PackageArtefacts -configxml C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\split.priconfig.xml -outputfile C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\Split\split.pri -indexname Untrusted.TestBundle -mappingfile AppX -verbose -overwrite

This creates the split .pri files as well as file maps that accompany the .pri files.

We use split.pri as the base for the main package and then the other .pri files for the split resource packages. We also use the split.map.txt file as our package's file map. So first, we copy split.map.txt to main.map.split.txt.

C:\Users\Darran\manual\TestBundle\PackageArtefacts>copy x64\Split\split.map.txt x64\main.map.split.txt

This file is then modified to add the rest of the package contents to the file map. To reiterate, this file map should only contain executable files and any other auxiliary files. The file map, main.map.split.txt would then contain:

[ResourceMetadata]
"ResourceDimensions"		"language-en-gb"
"ResourceDimensions"		"scale-200"

[Files]
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\Split\split.pri"			"resources.pri"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Wide310x150Logo.scale-200.png"			"Images\Wide310x150Logo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\StoreLogo.scale-200.png"			"Images\StoreLogo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.scale-200.png"			"Images\Square44x44Logo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-16.png"			"Images\Square44x44Logo.targetsize-16.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-16.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-16.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-16.png"			"Images\Square44x44Logo.altform-unplated_targetsize-16.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-24.png"			"Images\Square44x44Logo.targetsize-24.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-24.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-24.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-24.png"			"Images\Square44x44Logo.altform-unplated_targetsize-24.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-256.png"			"Images\Square44x44Logo.targetsize-256.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-256.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-256.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-256.png"			"Images\Square44x44Logo.altform-unplated_targetsize-256.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-32.png"			"Images\Square44x44Logo.targetsize-32.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-32.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-32.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-32.png"			"Images\Square44x44Logo.altform-unplated_targetsize-32.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.targetsize-48.png"			"Images\Square44x44Logo.targetsize-48.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-lightunplated_targetsize-48.png"			"Images\Square44x44Logo.altform-lightunplated_targetsize-48.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square44x44Logo.altform-unplated_targetsize-48.png"			"Images\Square44x44Logo.altform-unplated_targetsize-48.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\Square150x150Logo.scale-200.png"			"Images\Square150x150Logo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SplashScreen.scale-200.png"			"Images\SplashScreen.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\SmallTile.scale-200.png"			"Images\SmallTile.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LockScreenLogo.scale-200.png"			"Images\LockScreenLogo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\LargeTile.scale-200.png"			"Images\LargeTile.scale-200.png"
"C:\Users\Darran\manual\TestBundle\PackageArtefacts\Images\BadgeLogo.scale-200.png"			"Images\BadgeLogo.scale-200.png"
"C:\Users\Darran\manual\TestBundle\x64\TestBundle.exe"			"TestBundle.exe"
"C:\Users\Darran\manual\TestBundle\x64\TestBundle.pri"			"TestBundle.pri"
"C:\Users\Darran\manual\TestBundle\x64\TestBundle.winmd"			"TestBundle.winmd"
"C:\Users\Darran\manual\TestBundle\x64\TestComponent.dll"			"TestComponent.dll"
"C:\Users\Darran\manual\TestBundle\x64\TestComponent.pri"			"TestComponent.pri"
"C:\Users\Darran\manual\TestBundle\x64\TestComponent.winmd"			"TestComponent.winmd"

The makeappx command line to generate the package from this would be:

C:\Users\Darran\manual\TestBundle\PackageArtefacts>makeappx pack /l /h sha256 /m C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\AppxManifest.xml /f C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\main.map.split.txt /o /p C:\Users\Darran\manual\TestBundle\SplitPackages\TestBundle_1.0.0.0_x64.msix

You should then sign this package with your code signing certificate, if necessary.

signtool sign /fd SHA256 /a /sha1 <store certificate hash> C:\Users\Darran\manual\TestBundle\SplitPackages\TestBundle_1.0.0.0_x64.msix

Repeat steps 1-3 for all other platforms that you wish to support. Yes, it is important to make the package out of the main set of resources, and you need one of these packages for each platform you wish to support. If you are supporting all 3 WinUI 3 supported platforms, then you should have the following packages.

Step 4. Create the split resource packages.

The only thing left to do at this point is create the packages that contain the split resources. As mentioned already, these should be platform independent. Because of this, I will be using the x64 version of these resources. Visual Studio normally generates these from the last platform it creates the packages for when you use the Publish/Package and Publish option.

The goal is to create and sign a package for each of the remaining file maps created from the resource split. So the files map files named like split.language-xx.map.txt and split.scale-xxx.map.txt are going to be used. The command line is also almost the same as what was used previously for makeappx.

C:\Users\Darran\manual\TestBundle\PackageArtefacts>makeappx pack /r /l /h sha256 /m C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\AppxManifest.xml /f C:\Users\Darran\manual\TestBundle\PackageArtefacts\x64\Split\split.scale-100.map.txt /o /p C:\Users\Darran\manual\TestBundle\SplitPackages\TestBundle_1.0.0.0_scale-100.msix

There is the addition of the /r command line option. While we reference the same AppxManifest.xml file, we use a different file map and package name. That is it. Repeat this for the remaining scales and languages, sign each of these packages and you are finished.

At this point, you can bundle these packages up and prepare things for the store submission.

As already stated, these steps are the general steps you would use for everything. So if by WinUI, you mean system Xaml and WinUI 2, then these are the general steps you would use. There would be some differences in the AppxManifest.xaml file, but you should be able to find those out yourself by simply using Visual Studio to create a throwaway project, packaging it for sideloading and inspecting the intermediate files and output.