This documentation is archived and is not being maintained.

Control.ProcessCmdKey Method

Processes a command key.

[Visual Basic]
Protected Overridable Function ProcessCmdKey( _
   ByRef msg As Message, _
   ByVal keyData As Keys _
) As Boolean
[C#]
protected virtual bool ProcessCmdKey(
   ref Message msg,
 Keys keyData
);
[C++]
protected: virtual bool ProcessCmdKey(
 Message* msg,
 Keys keyData
);
[JScript]
protected function ProcessCmdKey(
   msg : Message,
 keyData : Keys
) : Boolean;

Parameters

msg
A Message, passed by reference, that represents the window message to process.
keyData
One of the Keys values that represents the key to process.

Return Value

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, allows the ContextMenu 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.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

.NET Framework Security: 

See Also

Control Class | Control Members | System.Windows.Forms Namespace

Show: