这让我很好奇,所以我编写了一个小型控制台应用程序来可视化如果您使用计时器进行此实验会发生什么:
Private WithEvents _t As New Timers.Timer With {.Enabled = True}
Private Sub _t_Elapsed(sender As Object, e As Timers.ElapsedEventArgs) Handles _t.Elapsed
Console.WriteLine("tick")
End Sub
Sub Main()
' let it tick for 5 seconds
Task.Delay(5000).Wait()
' destroy the current timer
Console.WriteLine("destroying this timer")
_t.Dispose()
_t = Nothing
' add a little pause
Task.Delay(1000).Wait()
' create a new timer
Console.WriteLine("creating a new timer")
_t = New Timers.Timer With {.Enabled = True}
' let it tick for 5 seconds
Task.Delay(5000).Wait()
End Sub
如果您运行此代码,您会发现它确实在_t
替换实例时附加了事件处理程序。我不知道它是怎么做到的,但神奇之处可能在于Handles
关键字。无论如何,答案是肯定的。