Expand Minimize

Control.ProcessKeyPreview Method

Previews a keyboard message.

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

[SecurityPermissionAttribute(SecurityAction.InheritanceDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
[SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
protected virtual bool ProcessKeyPreview(
	ref Message m
)

Parameters

m
Type: System.Windows.Forms.Message

A Message, passed by reference, that represents the window message to process.

Return Value

Type: System.Boolean
true if the message was processed by the control; otherwise, false.

This method is called by a child control when the child control receives a keyboard message. The child control calls this method before generating any keyboard events for the message. If this method returns true, the child control considers the message processed and does not generate any keyboard events. The m parameter contains the window message to preview. Possible values for the Message.Msg property are WM_CHAR, WM_KEYDOWN, WM_SYSKEYDOWN, WM_KEYUP, and WM_SYSKEYUP. The ProcessKeyPreview method simply sends the character to the parent's ProcessKeyPreview method, or returns false if the control has no parent. The Form class overrides this method to perform actual processing of dialog keys.

Notes to Inheritors

When overriding the ProcessKeyPreview method in a derived class, a control should return true to indicate that it has processed the key. For keys that are not processed by the control, the result of calling the base class's ProcessKeyPreview method should be returned.

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft