(Delphi)如和下载网络文件的例子

FTP下载: http://www.7880.com/Info/Article-19938be0.html
         http://community.csdn.net/Expert/topic/3300/3300012.xml?temp=5.028933E-02

FTP下载: TIdFTP控件 (Delphi7  Indy)

Http下载: (Delphi7)使用设计Indy控件下载网络文件  //////////
在Form1中添加控件：
  两个Indy控件:IdAntiFreeze1,IdHTTP1;
  一个按钮    :Button1;
  一个进度条  :PRogressBar1 显示下载速度

procedure TForm1.Button1Click(Sender: TObject);
var
  MyStream:TMemoryStream;
begin
  IdAntiFreeze1.OnlyWhenIdle:=False;//设置使程序有反应.
  MyStream:=TMemoryStream.Create;
  try
    IdHTTP1.Get('http://www.appcontrols.com/demos/exe/HTTPDemo.exe',MyStream);
  except
    Showmessage('没有下载成功!');
    MyStream.Free;
    Exit;
  end;
  MyStream.SaveToFile(ExtractFilePath(paramstr(0))+'HTTPDemo.zip');
  MyStream.Free;
  Showmessage('OK');
end;

procedure TForm1.IdHTTP1WorkBegin(Sender: TObject; AWorkMode: TWorkMode;
  const AWorkCountMax: Integer);
begin
  //开始下载前,将ProgressBar1的最大值设置为需要接收的数据大小.
  ProgressBar1.Max:=AWorkCountMax;
  ProgressBar1.Min:=0;
  ProgressBar1.Position:=0;
end;

procedure TForm1.IdHTTP1Work(Sender: TObject; AWorkMode: TWorkMode;
  const AWorkCount: Integer);
begin
  //接收数据的时候,进度将在ProgressBar1显示出来.
  ProgressBar1.Position:=ProgressBar1.Position+AWorkCount;
end;