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 := 30000;  
    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 := 0 to http.Response.RawHeaders.Count - 1 do  
   begin  
       tmp := http.Response.RawHeaders[i];  
      if pos('set-cookie: ', LowerCase(tmp)) = 0 then Continue;  
    tmp := Trim(Copy(tmp, Pos('Set-cookie: ', tmp) + Length('Set-cookie: '), Length(tmp)));  
    tmp := Trim(Copy(tmp, 0, Pos(';', tmp) - 1));  
      if cookie = '' then cookie := tmp else cookie := cookie + '; ' + tmp;  
end;  
if cookie <> '' then  
begin  
    for i := 0 to http.Request.RawHeaders.Count - 1 do  
    begin  
      tmp := http.Request.RawHeaders[i];  
      if Pos('cookie', LowerCase(tmp)) = 0 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 := -1;  
          i := Pos(Node, Data);  
         if i = 0 then Exit;  
             Result := 0;  
          while i <> 0 do  
          begin  
            Inc(Result);  
             Delete(Data, 1, i + Length(Node) - 1);  
            i := Pos(Node, Data);  
          end;  
    end;  
   begin  
      Result := TStringList.Create;  
　　Count := GetFieldCount(Data, Node);  
　　for i := 0 to Count - 1 do  
　　begin  
　　    j := Pos(Node, Data);  
　　    Result.Add(Copy(Data, 1, j - 1));  
　　    Delete(Data, 1, j + Length(Node) - 1);  
　　end;  
　　Result.Add(Data);  
　end;  
begin  
　Result := TStringList.Create;  
　try  
    List := split(Data, 'href=');  
     for i := 1 to List.Count - 1 do  
     begin  
      tmp := List[i];  
       tmp := Copy(tmp, 0, Pos('</a>', tmp) - 1);  
       tmp := Copy(tmp, 0, Pos('>', tmp) - 1);  
       if Pos(' ', tmp) <> 0 then  
  
          tmp := Copy(tmp, 0, Pos(' ', tmp) - 1);  
       tmp := Q_ReplaceStr(tmp, Char(34), '');  
     tmp := Q_ReplaceStr(tmp, Char(39), '');  
       if not Compare(CI.Key, tmp) then Continue;  
       if Copy(tmp, 1, 7) <> 'http://' then  
     begin  
         if Copy(tmp, 1, 1) = '.' then tmp := StringReplace(tmp, '.', '', []);  
       if Copy(tmp, 1, 1) = '.' then tmp := StringReplace(tmp, '.', '', []);  
        try  
         tmp := 'http://' + http.URL.Host + ':' + http.URL.Port + http.URL.Path + tmp;  
        except  
         end;  
       end;  
       if Result.IndexOf(tmp) <> -1 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 = 0 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 = 0 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)>0 then  
     My_Cookie:=LeftBStr(tmpcookie,Pos(';',tmpcookie)-1)  
else  
     My_Cookie:= tmpcookie;  
//  
aIdHTTP.Request.CustomHeaders.Clear;  
aIdHTTP.Request.CustomHeaders.Add('Cookie:'+My_COOKIE);  
  
end;  

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