diff -r 000000000000 -r f6eca6facd07 WndProcRetHook.cs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WndProcRetHook.cs	Sat Jun 14 12:51:25 2014 +0200
@@ -0,0 +1,135 @@
+//=============================================================================
+// COPYRIGHT: Prosoft-Lanz
+//=============================================================================
+//
+// $Workfile: WndProcRetHook.cs $
+//
+// PROJECT : CodeProject Components
+// VERSION : 1.00
+// CREATION : 19.02.2003
+// AUTHOR : JCL
+//
+// DETAILS : This class implement the WH_CALLWNDPROCRET Windows hook mechanism.
+//           From MSDN, Dino Esposito.
+//
+//           WindowCreate, WindowDestroye and WindowActivate user events.
+//
+//-----------------------------------------------------------------------------
+using System;
+using System.Runtime.InteropServices;
+using System.Diagnostics;
+
+namespace CodeProject.Win32API.Hook
+{
+	///////////////////////////////////////////////////////////////////////
+	#region Enum WndMessage
+
+	/// <summary>
+	/// windows message.
+	/// </summary>
+	public enum WndMessage : int
+	{
+		/// Sent to the dialog procedure immediately before the dialog is displayed.
+		WM_INITDIALOG = 0x0110,
+		/// Sent to the dialog procedure immediately before the dialog is displayed.
+		WM_UNKNOWINIT = 0x0127
+	}
+	#endregion
+
+	///////////////////////////////////////////////////////////////////////
+	#region Class WndProcRetEventArgs
+
+	/// Class used for WH_CALLWNDPROCRET hook event arguments.
+	public class WndProcRetEventArgs : EventArgs
+	{
+		/// wParam parameter.
+		public IntPtr wParam;
+		/// lParam parameter.
+		public IntPtr lParam;
+		/// CWPRETSTRUCT structure.
+		public CwPRetStruct cw;
+
+		internal WndProcRetEventArgs(IntPtr wParam, IntPtr lParam)
+		{
+			this.wParam = wParam;
+			this.lParam = lParam;
+			cw = new CwPRetStruct();
+			Marshal.PtrToStructure(lParam, cw);
+		}
+	}
+
+	/// <summary>
+	/// CWPRETSTRUCT structure.
+	/// </summary>
+	[StructLayout(LayoutKind.Sequential)]
+	public class CwPRetStruct
+	{
+		/// Return value.
+		public int lResult;
+		/// lParam parameter.
+		public int lParam;
+		/// wParam parameter.
+		public int wParam;
+		/// Specifies the message.
+		public WndMessage message;
+		/// Handle to the window that processed the message.
+		public IntPtr hwnd;
+	}
+
+	#endregion
+
+	///////////////////////////////////////////////////////////////////////
+	#region Class WndProcRetHook
+	
+	/// <summary>
+	/// Class to expose the windows WH_CALLWNDPROCRET hook mechanism.
+	/// </summary>
+	public class WndProcRetHook : WindowsHook
+	{
+		/// <summary>
+		/// WH_CALLWNDPROCRET hook delegate method.
+		/// </summary>
+		public delegate void WndProcEventHandler(object sender, WndProcRetEventArgs e);
+
+		private IntPtr hWndHooked;
+
+		/// <summary>
+		/// Window procedure event.
+		/// </summary>
+		public event WndProcEventHandler WndProcRet;
+
+		/// <summary>
+		/// Construct a WH_CALLWNDPROCRET hook.
+		/// </summary>
+		/// <param name="hWndHooked">
+		/// Handle of the window to be hooked. IntPtr.Zero to hook all window.
+		/// </param>
+		public WndProcRetHook(IntPtr hWndHooked) : base(HookType.WH_CALLWNDPROCRET)
+		{
+			this.hWndHooked = hWndHooked;
+			this.HookInvoke += new HookEventHandler(WndProcRetHookInvoked);
+		}
+		/// <summary>
+		/// Construct a WH_CALLWNDPROCRET hook giving a hook filter delegate method.
+		/// </summary>
+		/// <param name="hWndHooked">
+		/// Handle of the window to be hooked. IntPtr.Zero to hook all window.
+		/// </param>
+		/// <param name="func">Hook filter event.</param>
+		public WndProcRetHook(IntPtr hWndHooked, HookProc func) : base(HookType.WH_CALLWNDPROCRET, func)
+		{
+			this.hWndHooked = hWndHooked;
+			this.HookInvoke += new HookEventHandler(WndProcRetHookInvoked);
+		}
+
+		// handles the hook event
+		private void WndProcRetHookInvoked(object sender, HookEventArgs e)
+		{
+			WndProcRetEventArgs wpe = new WndProcRetEventArgs(e.wParam, e.lParam);
+			if ((hWndHooked == IntPtr.Zero || wpe.cw.hwnd == hWndHooked) && WndProcRet != null)
+				WndProcRet(this, wpe);
+			return;
+		}
+	}
+	#endregion
+}