显示 jpg、png、gif 图片及 gif 动画 回复 "格兰特" 的问题

问题来源: http://www.cnblogs.com/del/archive/2009/03/15/1412384.html#1477470

---

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses jpeg, GIFImg, pngimage;

{显示 jpg 图片}
procedure TForm1.Button1Click(Sender: TObject);
var
  jpg: TJPEGImage;
begin
  jpg := TJPEGImage.Create;
  jpg.LoadFromFile('C:\Temp\Test.jpg');
  Canvas.Draw(0, 0, jpg);
  jpg.Free;
end;

{显示 png 图片}
procedure TForm1.Button2Click(Sender: TObject);
var
  png: TPngImage;
begin
  png := TPngImage.Create;
  png.LoadFromFile('C:\Temp\Test.png');
  Canvas.Draw(0, 0, png);
  png.Free;
end;

{显示 gif 图片}
procedure TForm1.Button3Click(Sender: TObject);
var
  gif: TGIFImage;
begin
  gif := TGIFImage.Create;
  gif.LoadFromFile('C:\Temp\Test.gif');
  Canvas.Draw(0, 0, gif);
  gif.Free;
end;

{显示 gif 动画}
procedure TForm1.Button4Click(Sender: TObject);
var
  gif: TGIFImage;
begin
  gif := TGIFImage.Create;
  gif.LoadFromFile('C:\Temp\Test.gif');
  gif.Animate := True;

  with TImage.Create(Self) do begin
    Parent := Self;
    Left := 0;
    Top := 0;
    Picture.Assign(gif);
  end;

  gif.Free;
end;

end.