idhttp获取验证码范例

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient, IdHTTP,
  StdCtrls, jpeg // Delphi 提示找不到这个单元文件，晕, GIFImage //这个单元要自己手动添加的，不自带, WinInet;
 
type
  TForm1 = class(TForm)
    IdHTTP1: TIdHTTP;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.Button1Click(Sender: TObject);
const
 // url = 'http://ptlogin2.qq.com/getimage?aid=15000701&0.9129723031485226';
  url='http://www.0zer.cn/function/c_validcode.asp?name=loginvalid';
var
  ms: TMemoryStream;
  //jpg: TJPEGImage;
  te: TGIFImage;
begin
  ms := TMemoryStream.Create;
  //jpg := TJPEGImage.Create;
    te:=TGIFImage.Create;
   if InternetGetConnectedState(nil,0) then    //检测计算机是否联网需要引用WinInet
   begin
     IdHTTP1.Get(url, ms);
     ms.Position := 0;
 
    //jpg.LoadFromStream(ms);
     te.LoadFromStream(ms);
     Canvas.Draw(10, 10, te);
   end
   else
   begin
     ShowMessage('错误');
     //jpg.Free;
     te.Free;
     ms.Free;
   end;
end;
end.