C#获取网页内容的三种方式

.NET
520
0
0
2022-03-22
标签   C#

搜索网络,发现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;//获取或设置用于向Internet资源的请求进行身份验证的网络凭据
       Byte[] pageData = MyWebClient.DownloadData(“http://www.163.com”); //从指定网站下载数据
       string pageHtml = Encoding.Default.GetString(pageData); //如果获取网站页面采用的是GB2312,则使用这句            
       //string pageHtml = Encoding.UTF8.GetString(pageData); //如果获取网站页面采用的是UTF-8,则使用这句
       Console.WriteLine(pageHtml);//在控制台输入获取的内容
       using (StreamWriter sw = new StreamWriter("c:\\test\\ouput.html"))//将获取的内容写入文本
       {
           sw.Write(pageHtml);
       }
       Console.ReadLine(); //让控制台暂停,否则一闪而过了             
   }
   catch(WebException webEx) {
       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;
}