二把刀：异步调用web service并返回结果

    Private Sub btnUpdate_Click(sender As System.Object, e As System.EventArgs) Handles btnUpdate.Click        If Trim(txtInput.Text) <> "" Then            Dim svc As New fysem            AddHandler svc.CallInUpdateCompleted, New FYSEMSVC.CallInUpdateCompletedEventHandler(AddressOf retV)            svc.CallInUpdateAsync("myid", "pswd", Split(txtInput.Text, vbCrLf))            For i As Integer = 0 To 2 Step 0                If InStr(txtLog.Text, "END") > 0 Then Exit For                Threading.Thread.Sleep(2000)                txtLog.AppendText(svc.CallInUpdateStatus("myid", "pswd") & vbCrLf)                My.Application.DoEvents()            Next        End If    End Sub    Sub retV(sender As Object, e As CallInUpdateCompletedEventArgs)        txtLog.AppendText(e.Result & vbCrLf)    End Sub