Question

有没有办法在屏幕上没有UI的情况下执行此操作？目前我有这个小的非UI程序每隔60秒从3270大型机读取和写入信息到文本文件，假设用户想要在60秒等待的中间取消，我怎么能'听'为没有来自UI的任何事件的按键？

Answer 1

你需要某种界面来捕捉击键。

以下是在控制台应用程序中运行的示例（创建一个空白的并粘贴到defauklt模块中）

它允许在后台线程中处理“SOMETHING”，同时让GUI空闲以供用户输入命令。在这种情况下，只需一个简单的1秒延迟计数器到1000。

选项比较文字

Module Module1

Sub Main()
    Console.WriteLine("Enter ""Start"", ""Stop"", or ""Exit"".")
    Do
        Dim Com As String = Console.ReadLine
        Select Case Com
            Case "Start"
                Console.WriteLine(StartWork)
            Case "Stop"
                Console.WriteLine(StopWork)
            Case "Exit"
                Console.WriteLine("Quiting on completion")
                Exit Do
            Case Else
                Console.WriteLine("bad command Enter ""Start"", ""Stop"", or ""Exit"".")
        End Select
    Loop
End Sub

Public Function StartWork() As String
    If ThWork Is Nothing Then
        ThWork = New Threading.Thread(AddressOf Thread_Work)
        ThWork.IsBackground = False  'prevents killing the work if the user closes the window.
        CancelWork = False
        ThWork.Start()
        Return "Started Work"
    Else
        Return "Work Already Processing"
    End If
End Function

Public Function StopWork() As String
    CancelWork = True
    If ThWork Is Nothing Then
        Return "Work not currently running"
    Else
        Return "Sent Stop Request"
    End If
End Function

Public CancelWork As Boolean = False
Public ThWork As Threading.Thread = Nothing
Public dummyCounter As Integer = 0

Public Sub Thread_Work()
    Try
        Do
            dummyCounter += 1
            Console.Title = "Working ... #" & dummyCounter
            ' ###############
            ' do a SMALL PART OF YOUR WORK here to allow escape...
            ' ###############
            If dummyCounter >= 1000 Then
                Console.Title = "Work Done at #" & dummyCounter
                Exit Do
            ElseIf CancelWork Then
                Exit Do
            End If
            Threading.Thread.Sleep(1000) ' demo usage only.
        Loop
    Catch ex As Exception
        Console.WriteLine("Error Occured at #" & dummyCounter)
    End Try
    ThWork = Nothing
    If CancelWork Then
        Console.Title = "Work Stopped at #" & dummyCounter
    End If
End Sub

End Module

在线程处于休眠状态时，“聆听”按键

1 个答案: