C#获取网页内容的三种方式

时间:2021-07-15 01:34:18

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

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(“”); //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

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

1 HttpWebRequest httpReq; 2 HttpWebResponse httpResp; 3 4 string strBuff = ""; 5 char[] cbuffer = new char[256]; 6 int byteRead = 0; 7 8 string filename = @"c:\log.txt"; 9 ///定义写入流操作 10 public void WriteStream() 11 { 12 Uri httpURL = new Uri(txtURL.Text); 13 14 ///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 15 httpReq = (HttpWebRequest)WebRequest.Create(httpURL); 16 ///通过HttpWebRequest的GetResponse()方法建立HttpWebResponse,强制类型转换 17 18 httpResp = (HttpWebResponse) httpReq.GetResponse(); 19 ///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 20 21 ///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 22 Stream respStream = httpResp.GetResponseStream(); 23 24 ///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 25 26 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) 27 StreamReader respStreamReader = new StreamReader(respStream,Encoding.UTF8); 28 29 byteRead = respStreamReader.Read(cbuffer,0,256); 30 31 while (byteRead != 0) 32 { 33 string strResp = new string(cbuffer,0,byteRead); 34 strBuff = strBuff + strResp; 35 byteRead = respStreamReader.Read(cbuffer,0,256); 36 } 37 38 respStream.Close(); 39 txtHTML.Text = strBuff; 40 }

标签:

原文地址:https://www.cnblogs.com/jiangyunfeng/p/11560083.html