Контроль за изменением содержимого буфера обмена

Code:

unit Unit1;

{©Drkb v.3}

interface

uses

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms,

Dialogs, StdCtrls;

type

TForm1 = class(TForm)

   Memo1: TMemo;

   procedure FormCreate(Sender: TObject);

   procedure FormDestroy(Sender: TObject);

private

   hwndNextViewer: THandle;

   procedure WMChangeCbChain(var Message: TWMChangeCBChain); message WM_CHANGECBCHAIN;

   procedure WMDrawClipboard(var Message: TMessage); message WM_DRAWCLIPBOARD;

end;

var

Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);

begin

// Add the window to the clipboard viewer chain.

hwndNextViewer := SetClipboardViewer(Handle);

Memo1.Lines.Clear

end;

procedure TForm1.WMChangeCbChain(var Message: TWMChangeCBChain);

begin

with Message do

begin

   // If the next window is closing, repair the chain.

   if Remove = hwndNextViewer then

     hwndNextViewer := Next

   // Otherwise, pass the message to the next link.

   else

     if hwndNextViewer <> 0 then

       SendMessage(hwndNextViewer, Msg, Remove, Next);

end;

end;

// clipboard contents changed.

procedure TForm1.WMDrawClipboard(var Message: TMessage);

begin

// Pass the message to the next window in clipboard

// viewer chain.

Memo1.Lines.Add('Сhanged');

with Message do

   SendMessage(hwndNextViewer, Msg, WParam, LParam);

end;

procedure TForm1.FormDestroy(Sender: TObject);

begin

ChangeClipboardChain(Handle, hwndNextViewer);

end;

end.