直接采用Delphi自带的控件的INDY组件为例.新建一个工程,放上一个TIdHTTP控件,一个TIdAntiFreeze控件,一个TProgressBar用于显示下载进度.最后放上一个TButton用于开始执行我们的命令.代码如下:
procedure TForm1.Button1Click(Sender: TObject);//点击按钮的时候开始下载我们的文件
var
MyStream:TMemoryStream;
begin
IdAntiFreeze1.OnlyWhenIdle:=False;//设置使程序有反应.
MyStream:=TMemoryStream.Create;
try
IdHTTP1.Get('http://www.138soft.com/download/Mp3ToExe.zip',MyStream);//下载我站点的一个ZIP文件
except//INDY控件一般要使用这种try..except结构.
Showmessage('网络出错!');
MyStream.Free;
Exit;
end;
MyStream.SaveToFile('c:/Mp3ToExe.zip');
MyStream.Free;
Showmessage('OK');
end;
procedure TForm1.IdHTTP1WorkBegin(Sender: TObject; AWorkMode: TWorkMode;
const AWorkCountMax: Integer);//开始下载前,将ProgressBar1的最大值设置为需要接收的数据大小.
begin
ProgressBar1.Max:=AWorkCountMax;
ProgressBar1.Min:=0;
ProgressBar1.Position:=0;
end;
procedure TForm1.IdHTTP1Work(Sender: TObject; AWorkMode: TWorkMode;
const AWorkCount: Integer);//接收数据的时候,进度将在ProgressBar1显示出来.
begin
ProgressBar1.Position:=ProgressBar1.Position+AWorkCount;
end;
IdHTTP1的Get还有一种形式就是获取字符串:例如,上面的程序可以改写成:
procedure TForm1.Button1Click(Sender: TObject);
var
MyStr:String;
begin
IdAntiFreeze1.OnlyWhenIdle:=False;//设置使程序有反应.
try
MyStr:=IdHTTP1.Get('http://www.138soft.com/default.htm');
except
Showmessage('网络出错!');
Exit;
end;
Showmessage(MyStr);
end;
