C#网页信息采集方法汇总

本文实例总结了三种常用的C#网页信息采集方法。分享给大家供大家参考。具体实现方法如下：

一、通过HttpWebResponse 来获取

{ 
        string response = ""; 
        HttpWebResponse httpResponse = null; 
 
        //assert: user have access to URL  
        try 
        { 
            HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create(url); 
            httpRequest.Headers.Set("Pragma", "no-cache"); 
 
                // request.Headers.Set("KeepAlive", "true"); 
 
                httpRequest.CookieContainer = new CookieContainer(); 
 
 
 
                httpRequest.Referer = url; 
 
                httpRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727)"; 
 
               
 
            httpRequest.Credentials = System.Net.CredentialCache.DefaultCredentials; 
            httpResponse = (HttpWebResponse)httpRequest.GetResponse(); 
             
        } 
        catch (Exception ex) 
        { 
            throw new ApplicationException("HTTP 403 Access denied, URL: " + url, ex); 
        } 
 
        //if here, the URL is correct and the user has access  
        try 
        { 
            string strEncod = httpResponse.ContentType; 
            StreamReader stream; 
            if (strEncod.ToLower().IndexOf("utf") != -1) 
            { 
                stream = new StreamReader(httpResponse.GetResponseStream(), System.Text.Encoding.UTF8); 
            } 
            else 
            { 
                stream = new StreamReader(httpResponse.GetResponseStream(), System.Text.Encoding.Default); 
            } 
            
            char[] buff = new char[4000]; 
            stream.ReadBlock(buff,0,4000); 
            response = new string(buff); 
            stream.Close(); 
            httpResponse.Close(); 
        } 
        catch (Exception ex) 
        { 
            throw new ApplicationException("HTTP 404 Page not found, URL: " + url, ex); 
        } 
        return response; 
}</div>
 
二、通过 WebResponse 来获取

{
        WebResponse result = null; 
        string resultstring = ""; 
        try 
        { 
            WebRequest req = WebRequest.Create(url); 
            req.Timeout = 30000; 
            result = req.GetResponse(); 
            Stream ReceiveStream = result.GetResponseStream(); 
 
            //read the stream into a string 
            //StreamReader sr = new StreamReader(ReceiveStream, System.Text.Encoding.UTF8); 
            string strEncod = result.ContentType; 
            StreamReader sr; 
            if (strEncod.ToLower().IndexOf("utf") != -1) 
            { 
                sr = new StreamReader(ReceiveStream, System.Text.Encoding.UTF8); 
            } 
            else 
            { 
                sr = new StreamReader(ReceiveStream, System.Text.Encoding.Default); 
            } 
            resultstring = sr.ReadToEnd(); 
            js.alert(resultstring)