c# 獲取網頁源碼

C#獲取指定網頁HTML原代碼可使用 WebClient WebRequest HttpWebRequest 三種方式來實現。

當然也可使用webBrowse！在此就不研究webBrowse如何獲取了。

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”應與指定網頁的編碼對應。

總結

可以看到HttpWebRequest 方式最複雜，但確提供了更多的選擇性。

有的網站檢測客戶端的UserAgent！如163.com，你如果使用WebClient WebRequest方式獲取時，將獲取到的是錯誤提示頁面內容。

而通過HttpWebRequest 就沒問題。