Visual Basic .NET：计划

Question

是否可以在我的Visual Basic .NET窗体中检查每隔X个间隔执行一次函数？

Answer 1

查看Timer类。

Public Class Form1 
    Private T As Timer 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
     T = New Timer() 
     AddHandler T.Tick, AddressOf TimerTicker 
     T.Interval = (1000 * 3) 'Every 3 seonds 
     T.Start() 
    End Sub 
    Private Sub TimerTicker(ByVal sender As Object, ByVal ev As EventArgs) 
     Trace.WriteLine("here") 
    End Sub 
End Class 

Answer 2

你是说在某个时间间隔运行一个函数吗？如果是这样，那么定时器控制将工作。快速Google search会给你一些定时器教程。

Answer 3

这个怎么样：使用定时器，，只是用你想要的任何方法替换MessageBox警报。

以下示例实现了一个简单的间隔计时器，该计时器每五秒钟发出一次警报。发生警报时，MessageBox将显示警报已启动的次数并提示用户是否应继续运行计时器。

您可以找到更多详细信息here。

Public Class Class1 
>  Private Shared WithEvents myTimer As New System.Windows.Forms.Timer() 
>  Private Shared alarmCounter As Integer = 1 
>  Private Shared exitFlag As Boolean = False  

> 
>  ' This is the method to run when the timer is raised. 
>  Private Shared Sub TimerEventProcessor(myObject As 
> Object, _ 
>           ByVal myEventArgs As EventArgs) _ 
>          Handles myTimer.Tick 
>   myTimer.Stop() 
> 
>   ' Displays a message box asking whether to continue running the 
> timer. 
>   If MessageBox.Show("Continue running?", "Count is: " & 
> alarmCounter, _ 
>        MessageBoxButtons.YesNo) = 
> DialogResult.Yes Then 
>    ' Restarts the timer and increments the counter. 
>    alarmCounter += 1 
>    myTimer.Enabled = True 
>   Else 
>    ' Stops the timer. 
>    exitFlag = True 
>   End If 
>  End Sub 
> 
>  Public Shared Sub Main() 
>   ' Adds the event and the event handler for the method that will 
>   ' process the timer event to the timer. 
> 
>   ' Sets the timer interval to 5 seconds. 
>   myTimer.Interval = 5000 
>   myTimer.Start() 
> 
>   ' Runs the timer, and raises the event. 
>   While exitFlag = False 
>    ' Processes all the events in the queue. 
>    Application.DoEvents() 
>   End While 
> 
>  End Sub  
> 
> End Class