透過url去抓網頁資料回來

提供一段程式，可以透過 url 去將 url 所指定的網頁將網頁抓回並存成字串。

可以針對這回傳字串進行文字分析處理以取得我們想要的資訊。

http://docs.google.com/Doc?id=dfs2h99g_86dnpwqvc6

#region Retrieves the HTML from the specified URL.
/// <summary>
/// Retrieves the HTML from the specified URL.
/// </summary>
/// <param name="pageUrl">URL of the web page to retrive HTML.</param>
/// <param name="timeoutSeconds">The timeout for the http request.</param>
/// <returns>Returns the retrived HTML.</returns>
public string GetPageHTML(string pageUrl, int timeoutSeconds)
{
 System.Net.WebResponse response = null;

 try
 {
     // Setup our Web request
     System.Net.WebRequest request = System.Net.WebRequest.Create(pageUrl);
     request.Timeout = timeoutSeconds * 1000;

     // Retrieve data from request
     response = request.GetResponse();

     System.IO.Stream streamReceive = response.GetResponseStream();
     System.Text.Encoding encoding = System.Text.Encoding.GetEncoding("utf-8");
     //System.Text.Encoding encoding = System.Text.Encoding.GetEncoding("big5");
     //System.IO.StreamReader streamRead = new System.IO.StreamReader(streamReceive, System.Text.Encoding.Default);
     System.IO.StreamReader streamRead = new System.IO.StreamReader(streamReceive, System.Text.Encoding.UTF8);



     // return the retrieved HTML
     return streamRead.ReadToEnd();
 }
 catch (Exception ex)
 {
     // Error occured grabbing data, return empty string.
     //MessageBox.Show(this, "An error occurred while retrived the HTML content. " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
     return "";
 }
 finally
 {
     // Check if exists, then close the response.
     if (response != null)
     {
         response.Close();
     }
 }
}
#endregion

// for test
protected void btnGet_Click(object sender, EventArgs e)
{
 string AA=GetPageHTML(txtURL.Text.Trim(), 100);
 txtResult.Text = AA;
}

關鍵字：
streamReceive
GetResponseStream
encoding
streamRead

參考：透過 HTML Agility Pack 抓網頁資料