vb.net - StreamReader hangs if there is nothing to read

Question

i have this code to read the TCP stream:

  Function checkdata() As String
    Dim Stream As NetworkStream = client.GetStream()
    sr = New StreamReader(Stream)

    Dim s As String = sr.ReadLine() <------------
    Return s
  End Function

Problem is that if there is no new data on the stream, the code hangs on the marked line. Why? how can I solve this?

Answer 1

Can you use the .DataAvailable property of a NetworkStream?

Function checkdata() As String
    Dim Stream As NetworkStream = client.GetStream()
    If Stream.DataAvailable Then
        Dim SR = New StreamReader(Stream)
        Dim s As String = SR.ReadLine()
        Return s
    Else
        Return Nothing
    End If
End Function