From 933903f9a136ac413b89b86116af7014b20d120d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=BA=AD=E8=8C=82=20=E5=8F=B6?= <1160210343@qq.com>
Date: Sat, 8 Jun 2024 23:49:30 +0800
Subject: [PATCH] Add primary information & nearest monitor function in monitor
 info class.

---
 src/WinUIEx/MonitorInfo.cs | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/WinUIEx/MonitorInfo.cs b/src/WinUIEx/MonitorInfo.cs
index 4068a9f..e475671 100644
--- a/src/WinUIEx/MonitorInfo.cs
+++ b/src/WinUIEx/MonitorInfo.cs
@@ -4,6 +4,7 @@
 using Windows.Foundation;
 using System.Collections.Generic;
 using Windows.Win32;
+using System;
 
 namespace WinUIEx
 {
@@ -32,6 +33,31 @@ public unsafe static IList<MonitorInfo> GetDisplayMonitors()
             return list;
         }
 
+        /// <summary>
+        /// Gets the display monitor that is nearest to a given window.
+        /// </summary>
+        /// <param name="hwnd">Window handle</param>
+        /// <returns>The display monitor that is nearest to a given window, or null if no monitor is found.</returns>
+        public unsafe static MonitorInfo? GetNearestDisplayMonitor(IntPtr hwnd)
+        {
+            var nearestMonitor = PInvoke.MonitorFromWindow(new(hwnd), MONITOR_FROM_FLAGS.MONITOR_DEFAULTTONEAREST);
+            MonitorInfo? nearestMonitorInfo = null;
+            MONITORENUMPROC callback = new MONITORENUMPROC((HMONITOR monitor, HDC deviceContext, RECT* rect, LPARAM data) =>
+            {
+                if (monitor == nearestMonitor)
+                {
+                    nearestMonitorInfo = new MonitorInfo(monitor, rect);
+                    return false;
+                }
+                return true;
+            });
+            LPARAM data = new LPARAM();
+            bool ok = PInvoke.EnumDisplayMonitors(null, null, callback, data);
+            if (!ok)
+                Marshal.ThrowExceptionForHR(Marshal.GetLastWin32Error());
+            return nearestMonitorInfo;
+        }
+
         private readonly HMONITOR _monitor;
 
         internal unsafe MonitorInfo(HMONITOR monitor, RECT* rect)
@@ -69,6 +95,11 @@ internal unsafe MonitorInfo(HMONITOR monitor, RECT* rect)
         /// </remarks>
         public Rect RectWork { get; }
 
+        /// <summary>
+        /// Gets if the monitor is the the primary display monitor.
+        /// </summary>
+        public bool IsPrimary => _monitor == PInvoke.MonitorFromWindow(new(IntPtr.Zero), MONITOR_FROM_FLAGS.MONITOR_DEFAULTTOPRIMARY);
+
         /// <inheritdoc />
         public override string ToString() => $"{Name} {RectMonitor.Width}x{RectMonitor.Height}";