add ClipboardHook

src/Shared/HandyControl_Shared/HandyControl_Shared.projitems

@@ -6,7 +6,7 @@
     <SharedGUID>aac11083-faca-405d-9197-5c1212d65656</SharedGUID>
   </PropertyGroup>
   <PropertyGroup Label="Configuration">
-    <Import_RootNamespace>HandyControl_Shared</Import_RootNamespace>
+    <Import_RootNamespace>HandyControl</Import_RootNamespace>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(MSBuildThisFileDirectory)Controls\Attach\BackgroundSwitchElement.cs" />
@@ -271,6 +271,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\SingleOpenHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\ValidateHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\VisualHelper.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Tools\Hook\ClipboardHook.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Hook\KeyboardHook.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Hook\MouseHook.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Interop\BitmapHandle.cs" />

src/Shared/HandyControl_Shared/Tools/Hook/ClipboardHook.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Windows;
+using System.Windows.Interop;
+using HandyControl.Tools.Interop;
+
+namespace HandyControl.Tools
+{
+    public class ClipboardHook
+    {
+        private static HwndSource HWndSource;
+
+        private static IntPtr HookId = IntPtr.Zero;
+
+        public static event Action ContentChanged;
+
+        public static void Start()
+        {
+            if (HookId != IntPtr.Zero)
+            {
+                Stop();
+            }
+
+            HookId = new WindowInteropHelper(new Window()).EnsureHandle();
+            HWndSource = HwndSource.FromHwnd(HookId);
+            if (HWndSource != null)
+            {
+                HWndSource.AddHook(WinProc);
+                NativeMethods.AddClipboardFormatListener(HookId);
+            }
+        }
+
+        public static void Stop() => NativeMethods.RemoveClipboardFormatListener(HookId);
+
+        private static IntPtr WinProc(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam, ref bool handled)
+        {
+            if (msg == NativeMethods.WM_CLIPBOARDUPDATE)
+            {
+                ContentChanged?.Invoke();
+            }
+            return IntPtr.Zero;
+        }
+    }
+}

src/Shared/HandyControl_Shared/Tools/Interop/NativeMethods.cs

@@ -46,6 +46,7 @@ namespace HandyControl.Tools.Interop
             WM_MBUTTONDOWN = 0x0207,
             WM_MBUTTONUP = 0x0208,
             WM_MBUTTONDBLCLK = 0x0209,
+            WM_CLIPBOARDUPDATE = 0x031D,
             WM_USER = 0x0400,
             TB_GETBUTTON = WM_USER + 23,
             TB_BUTTONCOUNT = WM_USER + 24,
@@ -223,5 +224,13 @@ namespace HandyControl.Tools.Interop
 
         [DllImport(ExternDll.User32)]
         public static extern IntPtr GetDesktopWindow();
+
+        [DllImport(ExternDll.User32, SetLastError = true)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        public static extern bool AddClipboardFormatListener(IntPtr hwnd);
+
+        [DllImport(ExternDll.User32, SetLastError = true)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        public static extern bool RemoveClipboardFormatListener(IntPtr hwnd);
     }
 }