vb.net中如何判断一个URL请求是否存在?有例子,在线等
Private function UrlExists(ByVal url1 As String)as boolean
Dim _xmlhttp As New MSXML2.XMLHTTPClass
_xmlhttp.open( "HEAD ", url1, False, , )

_xmlhttp.send( " ")
If _xmlhttp.statusText = "OK " Then
return urlexists=true
Else
return urlexists=false
End If
End Sub

用上面这样做为什么不行??

[解决办法]
用这个代码试试
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);

request.Method = "GET ";
request.Timeout = 10;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
if (response.StatusCode == HttpStatusCode.OK )