Mega Code Archive

 
Categories / Delphi / API
 

Trapping the windows system key printscreen

Question: How can I globally trap the Windows system key "PrintScreen"? Answer: The following example demonstrates registering a hot key with the system to globally trap the windows printscreen key. Example: type TForm1 = class(TForm) procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); private { Private declarations } procedure WMHotKey(var Msg : TWMHotKey); message WM_HOTKEY; public { Public declarations } end; var Form1: TForm1; implementation {$R *.DFM} const id_SnapShot = 101; procedure TForm1.WMHotKey (var Msg : TWMHotKey); begin if Msg.HotKey = id_SnapShot then ShowMessage('GotIt'); end; procedure TForm1.FormCreate(Sender: TObject); begin RegisterHotKey(Form1.Handle, id_SnapShot, 0, VK_SNAPSHOT); end; procedure TForm1.FormDestroy(Sender: TObject); begin UnRegisterHotKey (Form1.Handle, id_SnapShot); end;