C#获取网页内容三种方法

C#通常有三种方法获取网页内容，使用WebClient、WebBrowser或者HttpWebRequest/HttpWebResponse。。。

# 方法一：使用WebClient

（引用自：<http://fbljava.blog.163.com/blog/static/265211742008712105145244>)

```#
static void Main(string[] args)
{
    try {
        WebClient MyWebClient = new WebClient();
        MyWebClient.Credentials = CredentialCache.DefaultCredentials;//设置网络凭据为默认
        Byte[] pageData = MyWebClient.DownloadData(“http://www.163.com”); //要下的网页
        string pageHtml = Encoding.Default.GetString(pageData);  //用默认编码[GB2312]获取网页          
        //string pageHtml = Encoding.UTF8.GetString(pageData); //下载编码为UTF-8获取网页
        Console.WriteLine(pageHtml);//Console显示网页
        using (StreamWriter sw = new StreamWriter("c:\\test\\ouput.html"))//写入文本
        {
            sw.Write(pageHtml);
        }
        Console.ReadLine(); //Console暂停
    }
    catch(WebException webEx) {//错误输出
        Console.WriteLine(webEx.Message.ToString());
    }
}
```

# 方法二：使用WebBrowser

(引用自：<http://topic.csdn.net/u/20091225/14/4ea221cd-4c1e-4931-a6db-1fd4ee7398ef.html>)

```#
WebBrowser web = new WebBrowser();
web.Navigate("http://www.xjflcp.com/ssc/");
web.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(web_DocumentCompleted);
void web_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            WebBrowser web = (WebBrowser)sender;
            HtmlElementCollection ElementCollection = web.Document.GetElementsByTagName("Table");
            foreach (HtmlElement item in ElementCollection)
            {
                 File.AppendAllText("Kaijiang_xj.txt", item.InnerText);
            }
        }
```

# 方法三：使用HttpWebRequest/HttpWebResponse

(引用自：<http://hi.baidu.com/onlyafar/blog/item/7ac4c6bf92d4810019d81f98.html>)

```#
HttpWebRequest httpReq;
HttpWebResponse httpResp;
string strBuff = "";
char[] cbuffer = new char[256];
int byteRead = 0;
string filename = @"c:\log.txt";
///定义写入流操作
public void WriteStream()
{
  Uri httpURL = new Uri(txtURL.Text);
  ///HttpWebRequest类继承于WebRequest，并没有自己的构造函数，需通过WebRequest的Creat方法建立，并进行强制的类型转换
  httpReq = (HttpWebRequest)WebRequest.Create(httpURL);
  ///通过HttpWebRequest的GetResponse()方法建立HttpWebResponse,强制类型转换
  httpResp = (HttpWebResponse) httpReq.GetResponse();
  ///GetResponseStream()方法获取HTTP响应的数据流,并尝试取得URL中所指定的网页内容
  ///若成功取得网页的内容，则以System.IO.Stream形式返回，若失败则产生ProtoclViolationException错误。在此正确的做法应将以下的代码放到一个try块中处理。这里简单处理
  Stream respStream = httpResp.GetResponseStream();
  ///返回的内容是Stream形式的，所以可以利用StreamReader类获取GetResponseStream的内容，并以
  StreamReader类的Read方法依次读取网页源程序代码每一行的内容，直至行尾（读取的编码格式：UTF8）
  StreamReader respStreamReader = new StreamReader(respStream,Encoding.UTF8);
  byteRead = respStreamReader.Read(cbuffer,0,256);
  while (byteRead != 0){
    string strResp = new string(cbuffer,0,byteRead);
    strBuff = strBuff + strResp;
    byteRead = respStreamReader.Read(cbuffer,0,256);
  }
  respStream.Close();
  txtHTML.Text = strBuff;
}
```