FileDataDropBox
To make DropBoxFileData work you will need a dropbox api key and a authorization token to get the api key you can go to this address https://dropbox.com/developers/apps when you have the api key you will need to generate an authorization token you can use this utility for that
https://github.com/egarim/FileDataDropBox/blob/master/DropBoxAuthGenerator.zip
To get the authorization token use the following command
BitFwks.DropBoxAuthGenerator.exe YourApiKey
Once you have the authorization token you need to add some parameters on the app/web.config as shown below
<appSettings>
<!-- ... -->
<add key="DropBoxFileDataDefaultFolder" value="NameOfMyFolderOnDropBox"/>
<add key="DropboxAccessToken" value="MyDropboxAccessToken"/>
<!-- ... -->
</appSettings>
</pre>
Now you can declare a DropBoxFileData as any other persistent property
DropBoxFileData attachment;
public DropBoxFileData Attachment
{
get => attachment;
set => SetPropertyValue(nameof(Attachment), ref attachment, value);
}