在不捕获异常的情况下检测404

简单功能:检查Web服务器是否返回非200 HTTP状态。

Private Function RemoteFileOk(ByVal Url As String) As Boolean
  Dim req As HttpWebRequest = TryCast(WebRequest.Create(Url), HttpWebRequest)
  req.Method = "HEAD"
  Dim rsp As HttpWebResponse = TryCast(req.GetResponse(), HttpWebResponse)
  Return (rsp.StatusCode = HttpStatusCode.OK)
End Function

我是从 this answer 在“上” How to check if a file exits on an webserver by its URL? ".

不幸的是,它不起作用:一个系统。网当抛出WebException时,远程服务器返回错误:(404)当url指向不存在的页面时找不到。我希望能够用HEAD请求(或类似的东西)探测服务器,然后处理404,而不必捕获异常。

我的解决方案如下:

Private Function RemoteFileOk(ByVal Url As String) As Boolean
  Dim req As HttpWebRequest = TryCast(WebRequest.Create(Url), HttpWebRequest)
  req.Method = "HEAD"
  Try
    Using rsp As HttpWebResponse = TryCast(req.GetResponse(), HttpWebResponse)
      Return (rsp.StatusCode = HttpStatusCode.OK)
    End Using
  Catch ex As WebException
    Return False
  End Try
End Function

能够 必须避免。

还有更整洁的方式吗?