PreFilterMessage Method
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IMessageFilter.PreFilterMessage Method (Message)


Filters out a message before it is dispatched.

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

[SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
bool PreFilterMessage(
	ref Message m


Type: System.Windows.Forms.Message

The message to be dispatched. You cannot modify this message.

Return Value

Type: System.Boolean

true to filter the message and stop it from being dispatched; false to allow the message to continue to the next filter or control.

Use PreFilterMessage to filter out a message before it is dispatched to a control or form. For example, to stop the Click event of a Button control from being dispatched to the control, you implement the PreFilterMessage method and return a true value when the Click message occurs. You can also use this method to perform code work that you might need to do before the message is dispatched.


Requires UnmanagedCode permission at link time.

.NET Framework
Available since 1.1
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