Question

使用WebClient类时，当响应状态为4xx时，是否有办法访问响应正文，例如：

(webClient, evt) => // this is the event handler for the UploadStringCompleted event
    {
        if (evt.Error != null)
        {
            // can I access the response text?
        }
    });

Answer 1

由于evt.Error是一个WebException（而不是一个vanilla异常），这就是我所做的（请原谅VB.NET）：

''' <summary>
''' Extends a WebException to include any body text from the HTTP Response in the .Message
''' </summary>
Friend Function ExtendWebExceptionInfo(ex As Exception) As Exception
    Dim wEx As WebException = TryCast(ex, WebException)
    If wEx Is Nothing Then Return ex

    Dim exMessage As String = Nothing
    Using reader As New StreamReader(wEx.Response.GetResponseStream, System.Text.Encoding.UTF8)
        exMessage = reader.ReadToEnd
    End Using
    If Not String.IsNullOrWhiteSpace(exMessage) Then
        exMessage = String.Format("{0}{1}{1}The server says:{1}{2}", wEx.Message, vbCrLf, exMessage)
        Return New WebException(exMessage, wEx, wEx.Status, wEx.Response)
    End If
    Return wEx
End Function

当服务器返回错误时，使用WebClient访问响应主体的任何方法？

1 个答案: