Control.ProcessCmdKey Method (System.Windows.Forms)

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ProcessCmdKey Method

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

Control..::.ProcessCmdKey Method

Processes a command key.

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

Syntax

Visual Basic (Declaration)

<SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags := SecurityPermissionFlag.UnmanagedCode)> _
<SecurityPermissionAttribute(SecurityAction.InheritanceDemand, Flags := SecurityPermissionFlag.UnmanagedCode)> _
Protected Overridable Function ProcessCmdKey ( _
    ByRef msg As Message, _
    keyData As Keys _
) As Boolean

Visual Basic (Usage)

Dim msg As Message
Dim keyData As Keys
Dim returnValue As Boolean

returnValue = Me.ProcessCmdKey(msg, _
    keyData)

[SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
[SecurityPermissionAttribute(SecurityAction.InheritanceDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
protected virtual bool ProcessCmdKey(
    ref Message msg,
    Keys keyData
)

Visual C++

[SecurityPermissionAttribute(SecurityAction::LinkDemand, Flags = SecurityPermissionFlag::UnmanagedCode)]
[SecurityPermissionAttribute(SecurityAction::InheritanceDemand, Flags = SecurityPermissionFlag::UnmanagedCode)]
protected:
virtual bool ProcessCmdKey(
    Message% msg, 
    Keys keyData
)

JScript

protected function ProcessCmdKey(
    msg : Message, 
    keyData : Keys
) : boolean

Parameters

msg: Type: System.Windows.Forms..::.Message%
A Message, passed by reference, that represents the window message to process.

keyData: Type: System.Windows.Forms..::.Keys
One of the Keys values that represents the key to process.

Return Value

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

Remarks

This method is called during message preprocessing to handle command keys. Command keys are keys that always take precedence over regular input keys. Examples of command keys include accelerators and menu shortcuts. The method must return true to indicate that it has processed the command key, or false to indicate that the key is not a command key. This method is only called when the control is hosted in a Windows Forms application or as an ActiveX control.

The ProcessCmdKey method first determines whether the control has a ContextMenu, and if so, enables the ContextMenu to process the command key. If the command key is not a menu shortcut and the control has a parent, the key is passed to the parent's ProcessCmdKey method. The net effect is that command keys are "bubbled" up the control hierarchy. In addition to the key the user pressed, the key data also indicates which, if any, modifier keys were pressed at the same time as the key. Modifier keys include the SHIFT, CTRL, and ALT keys.

Notes to Inheritors:

When overriding the ProcessCmdKey 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 ProcessCmdKey method should be returned. Controls will seldom, if ever, need to override this method.

.NET Framework Security

UIPermission
for all windows for inheriting classes to call this method. Associated enumeration: AllWindows value of UIPermissionWindow.

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

Reference

Control Class

Control Members

System.Windows.Forms Namespace