System.Net.WebException'发生在System.dll中，但未在用户代码中处理

Question

Try
Dim url = "something"
Dim request = WebRequest.Create(url)
request.Credentials = CredentialCache.DefaultCredentials
Dim httpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse)
Dim dataStream = httpWebResponse.GetResponseStream()
If dataStream Is Nothing Then
Return ""
End If
Dim reader = New StreamReader(dataStream)
Return reader.ReadToEnd()
Catch ex As WebException
Return ""
End Try

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上面的代码在 LocalHost 中工作，但在服务器中它不起作用并引发异常。

System.Net.WebException'发生在系统中.dll但未处理 在用户代码中

Answer 1

您在Catch之后重新引发异常。 删除Throw。

Try
Dim url = "something"
Dim request = WebRequest.Create(url)
request.Credentials = CredentialCache.DefaultCredentials
Dim httpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse)
Dim dataStream = httpWebResponse.GetResponseStream()
If dataStream Is Nothing Then
Return ""
End If
Dim reader = New StreamReader(dataStream)
Return reader.ReadToEnd()
Catch ex As WebException
Return ""
End Try