判断URL的HTTP状态

Public Class TestExist
    Public Shared Function UrlExist(ByVal sURL As String) As Boolean
        Dim temp As Boolean = False

        Try
            Dim request As HttpWebRequest = DirectCast(WebRequest.Create(sURL), HttpWebRequest)
            'WebProxy proxy = new WebProxy("your proxy server", 8080); 
            'request.Proxy = proxy; 
            request.Method = "HEAD"
            request.AllowAutoRedirect = False
            Dim response As HttpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse)


            Select Case response.StatusCode
                Case HttpStatusCode.OK
                    temp = True
                    Exit Select
                Case HttpStatusCode.Moved
                    temp = True
                    Exit Select
                Case HttpStatusCode.NotFound
                    temp = False
                    Exit Select
                Case HttpStatusCode.MultipleChoices
                    temp = True
                    Exit Select
                Case HttpStatusCode.Ambiguous
                    temp = True
                    Exit Select
                Case HttpStatusCode.MovedPermanently
                    temp = True
                    Exit Select
                Case HttpStatusCode.Moved
                    temp = True
                    Exit Select
                Case HttpStatusCode.Found
                    temp = True
                    Exit Select
                Case HttpStatusCode.Redirect
                    temp = True
                    Exit Select
                Case HttpStatusCode.SeeOther
                    temp = True
                    Exit Select
                Case HttpStatusCode.RedirectMethod
                    temp = True
                    Exit Select
                Case HttpStatusCode.NotModified
                    temp = True
                    Exit Select
                Case HttpStatusCode.UseProxy
                    temp = True
                    Exit Select
                Case HttpStatusCode.Unused
                    temp = True
                    Exit Select
                Case HttpStatusCode.TemporaryRedirect
                    temp = True
                    Exit Select
                Case HttpStatusCode.RedirectKeepVerb
                    temp = True
                    Exit Select
                Case Else
                    temp = False
            End Select
            response.Close()
        Catch ex As Exception
            temp = False
        End Try

        Return temp
    End Function
End Class