发送请求时出现400错误,错误代码为:webresponse = (httpwebresponse)webrequest.getresponse();

解决办法:抛出异常

httpwebresponse webresponse;
            try
            {
               
                webresponse = (httpwebresponse)webrequest.getresponse();   //请求页面信息
            }
            catch (webexception ex)
            {
                webresponse = (httpwebresponse)ex.response;   //获得错误发生时候服务器段错误页面的源代码
            }