Question

我正在制作试纸，那里有计数器。当用户点击下一个按钮时，我必须继续它。

我在表格3上用于计时器的代码是：

Public Class Form3
    Inherits System.Windows.Forms.Form

    Private alarmTime As Date

    Private Sub Form3_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load

    Me.alarmTime = Date.Now.AddMinutes(60)
    Me.Timer1.Start()


End Sub

Private Sub Timer1_Tick(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles Timer1.Tick

    If alarmTime < Date.Now Then
        Me.Timer1.Stop()
        MessageBox.Show("Time's up.")
    Else
        Dim remainingTime As TimeSpan = Me.alarmTime.Subtract(Date.Now)

        Me.Label6.Text = String.Format("{0}:{1:d2}:{2:d2}", _
                                       remainingTime.Hours, _
                                       remainingTime.Minutes, _
                                       remainingTime.Seconds)
    End If

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles Button1.Click

    Dim frmDialogue As New Form8

    frmDialogue.ShowDialog()

End Sub

Answer 1

我会将您计时器的所有代码放入Module。这样您就可以在应用程序的任何位置访问它。我还要添加两个新事件Elapsed和TimerComplete，以便多个对象和表单可以订阅您希望在执行时执行的关键操作计时器滴答。

以下是可从任何地方访问的AppTimer模块：

Module AppTimer
    Private alarmTime As Date
    Private WithEvents timer As Timer = New Timer()

    Public Sub Start(ByVal time as Date)
        alarmTime = time
        timer.Start()
    End Sub

    Public Sub TimerTick(ByVal sender As Object, ByVal e as EventArgs)
        Handles timer.Tick

        If alarmTime < Date.Now Then
            timer.Stop()
            RaiseEvent TimerComplete("Time's up.")
        Else
            Dim remainingTime As Timespan = alarmTime.Subtract(Date.Now)
            RaiseEvent Elapsed(remainingTime)
        End If
    End Sub

    'This will fire when the duration of the timer has elapsed
    Public Event TimerComplete As Action(Of String)

    'This will fire each time the timer ticks unless it's finished
    Public Event Elapsed As Action(Of Timespan)
End Module

现在在Form3_Load(...)你可以像这样设置计时器：

    AppTimer.Start(Date.Now.AddMinutes(60))

然后以任何形式，你希望在这些事件触发时做一些事情，创建两个新方法并用AddHandler连接它们：

AddHandler AppTimer.Elapsed, AddressOf HandleElapsed
AddHandler AppTimer.TimerComplete, AddressOf HandleComplete

Private Sub HandleElapsed(ByVal remainingTime As Timespan)
    Me.Label6.Text = String.Format("{0}:{1:d2}:{2:d2}", _
                                   remainingTime.Hours, _
                                   remainingTime.Minutes, _
                                   remainingTime.Seconds)
End Sub

Private Sub HandleComplete(ByVal message As String)
    MessageBox.Show(message)
End Sub

还值得注意的是，您可以使用lambdas：

连接事件

AddHandler AppTimer.Elapsed, Sub(remainingTime)
                                 String.Format("{0}:{1:d2}:{2:d2}", _
                                     remainingTime.Hours, _
                                     remainingTime.Minutes, _
                                     remainingTime.Seconds) 
                             End Sub

希望这有帮助。

Answer 2

你可以创建一个主mdi窗口来保存定时器，并且会有子窗口可以访问父定时器，甚至mdi本身可以关闭所有的测试纸形式并显示msg框以便在时间到了。

如何在下一个表格中继续相同的倒数计时器？

2 个答案: