Delphi IDHTTP用法详解（六种用法）

一、IDHTTP的基本用法  

IDHttp和WebBrowser一样，都可以实现抓取远端网页的功能，但是http方式更快、更节约资源，缺点是需要手动维护cook，连接等  

IDHttp的创建，需要引入IDHttp  

procedure InitHttp();
begin
    http := TIdHTTP.Create(nil);
    http.ReadTimeout := ;
    http.OnRedirect := OnRedirect;
    http.Request.Accept := 'image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, */*';
    http.Request.AcceptLanguage := 'zh-cn';
    http.Request.ContentType := 'application/x-www-form-urlencoded';
    http.Request.UserAgent := 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; Maxthon; .NET CLR 1.1.4322)';  

    http.ProxyParams.ProxyServer := '代理服务器地址';
    http.ProxyParams.ProxyPort := '代理服务器端口';
end;  

二、如何取得服务端返回的cookie信息，并添加到http的request对象中  

procedure Setcookie;
var
   i: Integer;
   tmp, cookie: String;
begin
   cookie := '';
   for i :=  to http.Response.RawHeaders.Count -  do
   begin
       tmp := http.Response.RawHeaders[i];
      if pos('set-cookie: ', LowerCase(tmp)) =  then Continue;
    tmp := Trim(Copy(tmp, Pos('Set-cookie: ', tmp) + Length('Set-cookie: '), Length(tmp)));
    tmp := Trim(Copy(tmp, , Pos(';', tmp) - ));
      if cookie = '' then cookie := tmp else cookie := cookie + '; ' + tmp;
end;
if cookie <> '' then
begin
    for i :=  to http.Request.RawHeaders.Count -  do
    begin
      tmp := http.Request.RawHeaders[i];
      if Pos('cookie', LowerCase(tmp)) =  then Continue;
      http.Request.RawHeaders.Delete(i);
      Break;
    end;
    http.Request.RawHeaders.Add('cookie: ' + cookie);
end;
end;  

三、如何取得网页中的所有连接，对代码做修改你也可以实现查找所有图片等等  

function GetURLList(Data: String): TStringList;
var
i: Integer;
List: TStringList;
tmp: String;  

function Split(Data, Node: String): TStringList;
   var
    Count, i, j: Integer;  

       function GetFieldCount(Data, Node: String): Integer;
      var
         i: Integer;
      begin
          Result := -;
          i := Pos(Node, Data);
         if i =  then Exit;
             Result := ;
          while i <>  do
          begin
            Inc(Result);
             Delete(Data, , i + Length(Node) - );
            i := Pos(Node, Data);
          end;
    end;
   begin
      Result := TStringList.Create;
　　Count := GetFieldCount(Data, Node);
　　for i :=  to Count -  do
　　begin
　　    j := Pos(Node, Data);
　　    Result.Add(Copy(Data, , j - ));
　　    Delete(Data, , j + Length(Node) - );
　　end;
　　Result.Add(Data);
　end;
begin
　Result := TStringList.Create;
　try
    List := split(Data, 'href=');
     for i :=  to List.Count -  do
     begin
      tmp := List[i];
       tmp := Copy(tmp, , Pos('</a>', tmp) - );
       tmp := Copy(tmp, , Pos('>', tmp) - );
       if Pos(' ', tmp) <>  then  

          tmp := Copy(tmp, , Pos(' ', tmp) - );
       tmp := Q_ReplaceStr(tmp, Char(), '');
     tmp := Q_ReplaceStr(tmp, Char(), '');
       if not Compare(CI.Key, tmp) then Continue;
       if Copy(tmp, , ) <> 'http://' then
     begin
         if Copy(tmp, , ) = '.' then tmp := StringReplace(tmp, '.', '', []);
       if Copy(tmp, , ) = '.' then tmp := StringReplace(tmp, '.', '', []);
        try
         tmp := 'http://' + http.URL.Host + ':' + http.URL.Port + http.URL.Path + tmp;
        except
         end;
       end;
       if Result.IndexOf(tmp) <> - then Continue;
          Result.Add(tmp);
     end;
   FreeAndNil(List);
except  

end;
end;  

四、如何模拟http的get方法打开一个网页  

function GetMethod(http: TIDhttp; URL: String; Max: Integer): String;
var
RespData: TStringStream;
begin
RespData := TStringStream.Create('');
try
    try
      Http.Get(URL, RespData);
      Http.Request.Referer := URL;
      Result := RespData.DataString;
    except
      Dec(Max);
      if Max =  then
      begin
        Result := '';
        Exit;
      end;
      Result := GetMethod(http, URL, Max);
    end;
finally
    FreeAndNil(RespData);
end;
end;  

五、如何模拟http的post方法提交一个网页  

function PostMethod(URL, Data: String; max: Integer): String;
var
PostData, RespData: TStringStream;
begin
RespData := TStringStream.Create('');
PostData := TStringStream.Create(Data);
try
    try
      if http = nil then Exit;
      Http.Post(URL, PostData, RespData);
      Result := RespData.DataString;
      http.Request.Referer := URL;
    except
      Dec(Max);
      if Max =  then
      begin
        Result := '';
        Exit;
      end;
      Result := PostMethod(URL, Data, Max);
    end;
finally
    http.Disconnect;
    FreeAndNil(RespData);
    FreeAndNil(PostData);
end;
end;  

六、伪造session  

var
My_Cookie,tmpcookie:string;  

begin
aIdHttp.Get('http://www.huochepiao.net/');
tmpcookie:=aIdHttp.Request.CustomHeaders.Values['Set-Cookie'];
   if Pos(';',tmpcookie)> then
     My_Cookie:=LeftBStr(tmpcookie,Pos(';',tmpcookie)-)
else
     My_Cookie:= tmpcookie;
//
aIdHTTP.Request.CustomHeaders.Clear;
aIdHTTP.Request.CustomHeaders.Add('Cookie:'+My_COOKIE);  

end;  

http://blog.****.net/yanjiaye520/article/details/8199016