NativeWindow.DefWndProc Method

Invokes the default window procedure associated with this window.

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

public void DefWndProc (
	ref Message m
public void DefWndProc (
	/** @ref */ Message m
Not applicable.



The message that is currently being processed.

Typically, you only call the DefWndProc method when you are intercepting window messages and would like the default window procedure to handle the message. DefWndProc should not be called to send a window message to the window; call the Win32 SendMessage function instead.

It is an error to call DefWndProc when the Handle property is 0.

Notes to Inheritors: Override this method in a derived class to implement generalized custom message handling for a specific native window or .NET Windows Forms Control. Custom processing can be performed before, after, or instead of a call to the base class implementation of this method, which performs standard message processing. In contrast, adding customized message handling for an application can be accomplished through the AddMessageFilter method of the Application class.

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0