Control.PreProcessMessage Method
Preprocesses keyboard or input messages within the message loop before they are dispatched.
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)] public virtual bool PreProcessMessage( ref Message msg )
Parameters
- msg
- Type: System.Windows.Forms.Message
A Message, passed by reference, that represents the message to process. The possible values are WM_KEYDOWN, WM_SYSKEYDOWN, WM_CHAR, and WM_SYSCHAR.
PreProcessMessage is called by the application's message loop to preprocess input messages before they are dispatched. Possible values for the msg parameter are WM_KEYDOWN, WM_SYSKEYDOWN, WM_CHAR, and WM_SYSCHAR.
When overriding PreProcessMessage, a control should return true to indicate that it has processed the message. For messages that are not processed by the control, the result of base.PreProcessMessage should be returned. Controls will typically override one of the more specialized methods such as IsInputChar, IsInputKey, ProcessCmdKey, ProcessDialogChar, or ProcessDialogKey instead of overriding PreProcessMessage.
- UIPermission
for all windows for inheriting classes to call this method. Associated enumeration: AllWindows value of UIPermissionWindow.
- UIPermission
for all windows for the immediate caller to call this method. Associated enumeration: AllWindows value of UIPermissionWindow.
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.
