asp.net下檢測遠端URL是否存在的三種方法

iDotNetSpace發表於2009-12-25
ASP.NET
private void Page_Load(object sender, System.EventArgs e)
{
string url1 = "http://s.jb51.net/";
string url2 = "http://www.jb51.net/images/logo.gif";
Response.Write("
  • 方法1：");
    Response.Write(url1 + " 存在：" + UrlExistsUsingHttpWebRequest(url1).ToString());
    Response.Write("
  • 方法2：");
    Response.Write(url1 + " 存在：" + UrlExistsUsingSockets(url1).ToString());
    Response.Write("
  • 方法3：");
    Response.Write(url1 + " 存在：" + UrlExistsUsingXmlHttp(url1).ToString());
    Response.Write("
  • 方法1：");
    Response.Write(url2 + " 存在：" + UrlExistsUsingHttpWebRequest(url2).ToString());
    Response.Write("
  • 方法3：");
    Response.Write(url2 + " 存在：" + UrlExistsUsingXmlHttp(url2).ToString());
    }
    private bool UrlExistsUsingHttpWebRequest(string url){
    try
    {
    System.Net.HttpWebRequest myRequest = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(url);
    myRequest.Method = "HEAD";
    myRequest.Timeout = 100;
    System.Net.HttpWebResponse res = (System.Net.HttpWebResponse)myRequest.GetResponse();
    return (res.StatusCode == System.Net.HttpStatusCode.OK);
    }
    catch (System.Net.WebException we)
    {
    System.Diagnostics.Trace.Write(we.Message);
    return false;
    }
    }
    private bool UrlExistsUsingXmlHttp(string url)
    {
    //注意：此方法需要引用Msxml2.dll
    MSXML2.XMLHTTP _xmlhttp = new MSXML2.XMLHTTPClass();
    _xmlhttp.open("HEAD", url, false, null, null);
    _xmlhttp.send("");
    return (_xmlhttp.status == 200);
    }
    private bool UrlExistsUsingSockets(string url)
    {
    if (url.StartsWith("http://")) url = url.Remove(0, "http://".Length);
    try
    {
    System.Net.IPHostEntry ipHost = System.Net.Dns.Resolve(url);
    return true;
    }
    catch (System.Net.Sockets.SocketException se)
    {
    System.Diagnostics.Trace.Write(se.Message);
    return false;
    }
    }

    來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/12639172/viewspace-623596/，如需轉載，請註明出處，否則將追究法律責任。

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