unit unitFrmMain;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, Clipbrd; //加入clipbrd單元

type
  TForm1 = class(TForm)
    ListBox1: TListBox;
    Label1: TLabel;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    //觀察鏈中下一個窗口句柄
    NextClipHwnd: HWND;
    //處理WM_DRAWCLIPBOARD消息過程
    procedure WMDrawClipBoard(var AMessage: TMessage); message WM_DRAWCLIPBOARD;
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

{ TForm1 }

procedure TForm1.WMDrawClipBoard(var AMessage: TMessage);
begin
  //將WM_DRAWCLIPBOARD
  //消息傳遞到下一個觀察鏈中的窗口
  SendMessage(NextClipHwnd, AMessage.Msg, AMessage.WParam, AMessage.LParam);
  //查詢剪貼板中特定格式的數據內容
  if (Clipboard.HasFormat(CF_TEXT) or Clipboard.HasFormat(CF_OEMTEXT)) then
    begin
      //處理剪貼板中內容
      ListBox1.Items.Add(Clipboard.asText);
    end;

end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  //獲得觀察鏈中下一個窗口句柄
  NextClipHwnd := SetClipBoardViewer(Handle);

end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  //從觀察鏈中刪除本觀察窗口
  ChangeClipboardChain(Handle, NextClipHwnd);
  //將WM_DRAWCLIPBOARD消息傳遞到下一個觀察鏈中的窗口
  SendMessage(NextClipHwnd, WM_CHANGECBCHAIN, Handle, NextClipHwnd);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  ListBox1.Clear;
end;

end.