未在 Handles
子句中提供 WithEvents
变量。 过程声明末尾的 Handles
关键字使其处理由使用 WithEvents
关键字声明的对象变量引发的事件。
错误 ID:BC30506
更正此错误
提供必要的 WithEvents
变量。
示例
在以下示例中,Visual Basic 生成编译器错误 BC30506
,因为 System.Timers.Timer 实例的定义中未使用 WithEvents 关键字。
Imports System.Timers
Module Module1
Private _timer1 As New Timer() With {.Interval = 1000, .Enabled = True}
Sub Main()
Console.WriteLine("Press any key to start the timer...")
Console.ReadKey()
_timer1.Start()
Console.ReadKey()
End Sub
Private Sub Timer1_Tick(sender As Object, args As EventArgs) Handles _timer1.Elapsed
Console.WriteLine("Press any key to terminate...")
End Sub
End Module
以下示例编译成功,因为 _timer1
变量是通过 WithEvents
关键字定义的:
Imports System.Timers
Module Module1
Private WithEvents _timer1 As New Timer() With {.Interval = 1000}
Sub Main()
Console.WriteLine("Press any key to start the timer...")
Console.ReadKey()
_timer1.Start()
Console.ReadKey()
End Sub
Private Sub Timer1_Tick(sender As Object, args As EventArgs) Handles _timer1.Elapsed
Console.WriteLine("Press any key to terminate...")
End Sub
End Module