網頁抓取又稱之爲網絡爬蟲,咱們用來獲取目標網站、目標模塊的最新動態,能夠直接抓取過來。 咱們提供抓取目標的url地址,而後寫一個方法,抓取目標url的東西。c#
<!-- lang: c# --> //獲取某個URL下的內容 public string getContextByUrl(string url) { WebRequest request = WebRequest.Create(url); HttpWebResponse response = (HttpWebResponse)request.GetResponse(); Stream dataStream = response.GetResponseStream(); StreamReader reader = new StreamReader(dataStream,Encoding.Default); string result = reader.ReadToEnd(); reader.Close(); dataStream.Flush(); dataStream.Close(); response.Close(); return result; }
而後咱們調用此方法網絡
<!-- lang: c# --> string result = getContextByUrl(url); string name = result.Substring(result.IndexOf("tb-detail-hd"), 450); string aa = name.Substring(name.IndexOf("<h3>"), 50); string price = null; if (url.Contains("detail")) { price = result.Substring(result.IndexOf("<strong>"), 50); } else if (url.Contains("item")) { price = result.Substring(result.IndexOf("<strong class>"), 50); } Label1.Text = aa; Label2.Text = price;