NativeWindow::Handle Property


The .NET API Reference documentation has a new home. Visit the .NET API Browser on to see the new experience.

Gets the handle for this window.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

property IntPtr Handle {
	virtual IntPtr get() sealed;

Property Value

Type: System::IntPtr

If successful, an IntPtr representing the handle to the associated native Win32 window; otherwise, 0 if no handle is associated with the window.

Use this method when calling Windows API methods that require a handle for a window or control.

The following code example demonstrates creating a window with a specific operating system window class name. The example creates a class that inherits from NativeWindow to accomplish this. The example also demonstrates overriding the OnHandleChange method to be notified when the Handle changes.

The MyNativeWindow class creates a new window with the ClassName set to BUTTON. This creates a Win32 button window. The location and size of the button is set, along with specifying additional window styles. The class demonstrates how to use the CreateHandle method and override the WndProc method to intercept window messages that are received. Although the example looks for the WM_ACTIVATEAPP message, this could be replaced in a real program with window messages specific to the type created.


Some control types send their window messages to the window parent instead of the window. See the Windows Platform SDK for more information.

// MyNativeWindow class to create a window given a class name.
ref class MyNativeWindow: public NativeWindow

   // Constant values were found in the S"windows.h" header file.
   literal int WS_CHILD = 0x40000000,WS_VISIBLE = 0x10000000,WM_ACTIVATEAPP = 0x001C;
   int windowHandle;

   MyNativeWindow( Form^ parent )
      CreateParams^ cp = gcnew CreateParams;

      // Fill in the CreateParams details.
      cp->Caption = "Click here";
      cp->ClassName = "Button";

      // Set the position on the form
      cp->X = 100;
      cp->Y = 100;
      cp->Height = 100;
      cp->Width = 100;

      // Specify the form as the parent.
      cp->Parent = parent->Handle;

      // Create as a child of the specified parent
      cp->Style = WS_CHILD | WS_VISIBLE;

      // Create the actual window
      this->CreateHandle( cp );


   // Listen to when the handle changes to keep the variable in sync

   virtual void OnHandleChange() override
      windowHandle = (int)this->Handle;

   virtual void WndProc( Message % m ) override
      // Listen for messages that are sent to the button window. Some messages are sent
      // to the parent window instead of the button's window.
      switch ( m.Msg )
         case WM_ACTIVATEAPP:

            // Do something here in response to messages
      NativeWindow::WndProc( m );

.NET Framework
Available since 1.1
Return to top