asp.net c# 获取网页源码三种方式

C#获取指定网页HTML原代码可使用 WebClient WebRequest HttpWebRequest 三种方式来实现。
WebClient
private string GetWebClient(string url)
{
string strHTML ="";
WebClient myWebClient =new WebClient();
Stream myStream = myWebClient.OpenRead(url);
StreamReader sr =new StreamReader(myStream, System.Text.Encoding.GetEncoding("utf-8"));
strHTML = sr.ReadToEnd();
myStream.Close();
return strHTML;
}

WebRequest

private string GetWebRequest(string url)
{
Uri uri =new Uri(url);
WebRequest myReq = WebRequest.Create(uri);
WebResponse result = myReq.GetResponse();
Stream receviceStream = result.GetResponseStream();
StreamReader readerOfStream =new StreamReader(receviceStream, System.Text.Encoding.GetEncoding("utf-8"));
string strHTML = readerOfStream.ReadToEnd();
readerOfStream.Close();
receviceStream.Close();
result.Close();
return strHTML;
}

HttpWebRequest

private string GetHttpWebRequest(string url)
{
Uri uri =new Uri(url);
HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(uri);
myReq.UserAgent ="User-Agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705";
myReq.Accept ="*/*";
myReq.KeepAlive =true;
myReq.Headers.Add("Accept-Language","zh-cn,en-us;q=0.5");
HttpWebResponse result = (HttpWebResponse)myReq.GetResponse();
Stream receviceStream = result.GetResponseStream();
StreamReader readerOfStream =new StreamReader(receviceStream, System.Text.Encoding.GetEncoding("utf-8"));
string strHTML = readerOfStream.ReadToEnd();
readerOfStream.Close();
receviceStream.Close();
result.Close();
return strHTML;
}
注意“utf-8”应与指定网页的编码对应。
总结
可以看到HttpWebRequest 方式最复杂，但确提供了更多的选择性