我有一个后台工作控件,设置为执行任务并使用委托过程更新我的主UI中的多行文本框。这一切都工作得非常完美,但是一旦更新内容超出文本框底部,滚动条会出现,但持续刷新会导致文本框锁定在顶部。理想情况下,我希望文本框能够自动滚动到底部,以实时显示最新条目。最佳实现方式是什么?
我已经尝试使用 scrolltocaret()
方法,带或不带 SelectionStart = txtlog.Text.Length
命令。也许我把它放错了位置?
以下是一些代码示例:
委托代码:
Delegate Sub updateresults_delegate(ByVal textbox As TextBox, ByVal text As String)
Private Sub updatelog_threadsafe(ByVal textbox As TextBox, ByVal text As String)
If textbox.InvokeRequired Then
Dim mydelegate As New updateresults_delegate(AddressOf updatelog_threadsafe)
Me.Invoke(mydelegate, New Object() {textbox, text})
'Me.txtlog.SelectionStart = txtlog.Text.Length
'Me.txtlog.ScrollToCaret()
Else
textbox.Text = text
End If
End Sub
主背景工作活动:
For i As Integer = val1 To val2
'generate an IP address from split host parts and current value of i
host = s1(0) & "." & s1(1) & "." & s1(2) & "." & i
Try 'attempt to ping the IP
Dim reply As PingReply = pingsender.Send(host, timeoutval, buffer, options)
If reply.Status = IPStatus.Success Then
name = System.Net.Dns.GetHostEntry(host)'get DNS entry
resulttext += String.Format("{1} - {2}: reply: Bytes={3} time{4} TTL={5}{0}", vbCrLf, name.HostName, reply.Address.ToString, reply.Buffer.Length, getms(reply.RoundtripTime), reply.Options.Ttl) 'print out success text
Else
resulttext += String.Format(" {1}: Ping failed. {2}{0}", vbCrLf, host, reply.Status.ToString) 'print out fail text
End If
updatelog_threadsafe(txtlog, resulttext) 'send text to textbox
System.Threading.Thread.Sleep(1000)
Catch ex As Exception
End Try
Next
我想我的主要问题是:我相当确定textbox.scrolltocaret()
是我想要使用的正确方法,但最好把它放在哪里呢?我已经尝试将它放在委托、主后台工作程序中以及在runworkerasync()
方法之前和之后,但这些都没有起作用,现在我感到困惑!