todo WebClient学习

[HttpGet]
public ContentResult VerifyProduct(string jsoncallback,string code)
{
code = code.ToUpper();//全部转换成大写
string result = string.Empty;
if (!string.IsNullOrEmpty(code) && code.Length >= 11)//截取前11位
{
code = code.Substring(0, 11);
}
try
{
string postString = "code=" + code;//这里即为传递的参数，可以用工具抓包分析，也可以自己分析，主要是form里面每一个name都要加进来
byte[] postData = Encoding.UTF8.GetBytes(postString);//编码，尤其是汉字，事先要看下抓取网页的编码方式
string url = "http://h41105.www4.hp.com/ok/cn/zh/verify.asp";//地址

#region 模拟Post请求
WebClient webClient = new WebClient();
webClient.Headers.Add("User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)");
webClient.Headers.Add("Accept: text/html, application/xhtml+xml, */*");
webClient.Headers.Add("Content-Type: application/x-www-form-urlencoded");//采取POST方式必须加的header，如果改为GET方式的话就去掉这句话即可
webClient.Headers.Add("Host: h41105.www4.hp.com");
#region 代理设置
if ("1".Equals(IsWebProxy))
{
WebProxy wp = new WebProxy("http://" + WebProxyURL + ":" + WebProxyPort + "", true);
NetworkCredential credential = new NetworkCredential(CredentialUserName, CredentialPassword, Domain);
wp.Credentials = credential;
webClient.Proxy = wp;
}
#endregion
webClient.Headers.Add("Accept-Language: zh-CN");
webClient.Headers.Add("Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7");
#endregion

#region 返回结果
byte[] responseData = webClient.UploadData(url, "POST", postData);//得到返回字符流
string srcString = Encoding.UTF8.GetString(responseData);//解码
string keyWords = String.Concat("产品 ", code, " 为正品");//返回内容的关键字
string keyWords2 = String.Concat("产品 ", code, " 无效");
string keyWords3 = "输入的序列号出错。请检查防伪标签并重试。";//核查情况

#endregion

#region 根据返回结果判断显示内容

if (srcString.IndexOf(keyWords) > -1)//根据关键字 进行查找
{
result = String.Concat("产品 ", code, " 为正品");//正品
}
else if (srcString.IndexOf(keyWords2) > -1)
{
result = String.Concat("产品 ", code, " 无效");//无效
}
else if (srcString.IndexOf(keyWords3) > -1)
{
result = "输入的序列号出错。请检查防伪标签并重试。";
}
else { result = "请稍后再试"; }//验证失败，其它原因
#endregion

}
catch(System.Net.WebException webx)
{
result = "请稍后再试";
log.Error("VerifyProduct_WebException=" + webx.ToString() + ",wex.Status=" + webx.Status);
}
catch (Exception ex)
{
result = "请稍后再试";
log.Error("VerifyProduct_Error", ex);
}

string output = JavaScriptConvert.SerializeObject(result);
return Content(jsoncallback + "(" + output + ")");
}