unit Unit1;

interface

uses

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

  Dialogs, StdCtrls, ExtCtrls,

  Clipbrd, jpeg; //Clipboard使用

type

  TForm1 = class(TForm)

    Image1: TImage;

    ListBox1: TListBox;

    Image2: TImage;

    procedure FormCreate(Sender: TObject);

    procedure FormClose(Sender: TObject; var Action: TCloseAction);

    procedure ListBox1Click(Sender: TObject);

  private

    { Private declarations }

    //处理WM_DRAWCLIPBOARD消息过程

    procedure WMDrawClipBoard(var AMessage:TMessage);message WM_DRAWCLIPBOARD;

  public

    { Public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

var

  //观察链中下一个窗口句柄

  NextClipHwnd:HWND;

{ TForm1 }

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);

begin

  //从观察链中删除本观察窗口

  ChangeClipboardChain(Handle, NextClipHwnd);

  //将WM_DRAWCLIPBOARD消息传递到下一个观察链中的窗口

  SendMessage(NextClipHwnd, WM_CHANGECBCHAIN, Handle, NextClipHwnd);

end;

procedure TForm1.FormCreate(Sender: TObject);

begin

  //获得观察链中下一个窗口句柄

  NextClipHwnd := SetClipBoardViewer(Handle);

end;

procedure TForm1.ListBox1Click(Sender: TObject);

begin

  if ListBox1.Items.Count >= 0 then          

    if ListBox1.Items.Strings[ListBox1.ItemIndex]  ='Bitmap'  then

      begin

        Clipboard.Open;

        Clipboard.Clear;

        Clipboard.SetAsHandle(CF_BITMAP, Image1.Picture.Bitmap.Handle);

        Clipboard.Close;

      end

    else

    begin

      Clipboard.Open;

      ClipBoard.Clear;

      Clipboard.AsText := ListBox1.Items.Strings[ListBox1.ItemIndex];

      ClipBoard.Close;

    end;

end;

procedure TForm1.WMDrawClipBoard(var AMessage: TMessage);

begin

  //将WM_DRAWCLIPBOARD消息传递到下一个观察链中的窗口

  if NextClipHwnd <> 0 then

    SendMessage(NextClipHwnd, AMessage.Msg, AMessage.WParam, AMessage.LParam);

  //处理剪贴板中内容

  if Clipboard.HasFormat(CF_TEXT) or Clipboard.HasFormat(CF_OEMTEXT) then

  begin

    //查询剪贴板中特定格式的数据内容

    ListBox1.Items.Add(Clipboard.asText + '...');

  end;

  if Clipboard.HasFormat(CF_BITMAP) then

  begin

    ListBox1.Items.Add('Bitmap');

    Image1.Picture.Bitmap.LoadFromClipboardFormat(CF_BITMAP, clipboard.GetAsHandle(CF_BITMAP), 0);

  end;

end;

end.