关于vb.net的invoke，请各位指教。

[eric83326]

    Public Sub UpdateUI()
        Dim mrs As New Thread(AddressOf MonitorRASStatusAsync)
        mrs.Abort()
        Dim newDelegate As New UIDelegate(AddressOf UpdateUI)
        If Me.InvokeRequired Then
            Me.Invoke(newDelegate)
        Else
            Label2.Visible = True
            state.Text = "连接已断开"
            username.Visible = True
            userpass.Visible = True
            connect.Enabled = True
            remember.Visible = True
        End If
        If autoredial.Checked = True Then
            If Me.InvokeRequired Then
                Me.Invoke(newDelegate)
            Else
                Label2.Visible = False
                state.Text = "正在连接中"
                username.Visible = False
                userpass.Visible = False
                connect.Enabled = False
                remember.Visible = False
            End If
            Call dial()
        End If
    End Sub

以上代码里，Call dial()会被执行三次，何故？要怎样才能让它只执行一次，通过获取连接状态貌似不行，不管连接建立还是连接断开，其rasconnstate的值都是8192。
还有在断开按钮那里，如果重拨过了，那么rashangup(hrasconn)完全没用，很是奇怪。

[兔子-顾问]

只是走读代码，给出点建议
Me.Invoke(newDelegate)
每次执行完后，加一句return

[eric83326]

我已经知道原因了，现在在想怎么改，不过return的确没用，要么不执行call dial()，要么执行三遍。

[兔子-顾问]

    Public Sub UpdateUI()
        Dim mrs As New Thread(AddressOf MonitorRASStatusAsync)' 定义线程，但没启动
        mrs.Abort()'停止了
        Dim newDelegate As New UIDelegate(AddressOf UpdateUI)'声明委托
        If Me.InvokeRequired Then'如果跨线程调用
            '通过委托，调用UpdateUI，相当于递归调用自己了，调用完成后继续执行
            Me.Invoke(newDelegate)
        Else
            Label2.Visible = True
            state.Text = "连接已断开"
            username.Visible = True
            userpass.Visible = True
            connect.Enabled = True
            remember.Visible = True
        End If
        '如果跨线程调用，则执行完invoke后也会执行到这里，但下面直接访问了ui
        If autoredial.Checked = True Then
            If Me.InvokeRequired Then'如果跨线程访问ui
                Me.Invoke(newDelegate)'再次递归调用自己
            Else
                Label2.Visible = False
                state.Text = "正在连接中"
                username.Visible = False
                userpass.Visible = False
                connect.Enabled = False
                remember.Visible = False
            End If
            Call dial()
        End If
    End Sub

[eric83326]

        Dim newDelegate As New UIDelegate(AddressOf UpdateUI)
        If Me.InvokeRequired Then
            Me.Invoke(newDelegate)
        Else
            Label2.Visible = True
            state.Text = "连接已断开"
            username.Visible = True
            userpass.Visible = True
            connect.Enabled = True
            remember.Visible = True
            If autoredial.Checked = True Then
                
                Label2.Visible = False
                state.Text = "正在连接中"
                username.Visible = False
                userpass.Visible = False
                connect.Enabled = False
                remember.Visible = False
                Call dial()
            End If
        End If

改成这样，就只执行一次了，而且也可以在重拨后手动断开。