Vb.net 我应该如何修改此代码以适应异步行为？

我有一个钮扣。如果按下按钮，我希望所有按钮都被禁用。那我想做点什么。完成后，我希望所有按钮都重新启用

简单对吧

这是密码

Public Sub startAndStopClickingButton(ByVal sender As Object, ByVal SomeSub As System.Action)
    startClickingButton(sender)
    SomeSub.Invoke()
    stopClickingButton(sender)
End Sub

那么我会的

Private Sub Button2_Click_1(sender As Object, e As EventArgs) Handles cmdGroupRepeat.Click
    startAndStopClickingButton(sender, Sub()
                                           finRepeatOrdering() ' this one never end
                                           Dim b = 1
                                       End Sub)
End Sub

它工作得很好。调用Startclickingbutton。然后我调用任何lambda是在中间。然后在它完成后（实际上从来都不是），调用stopclickingbutton。简单

然后我改变了我的计划。finRepeatOrdering现在是finRepeatOrderingAsync

然而，我仍然想要同样的行为。我想等待finRepeatOrderingAsync完成，然后再单击停止按钮

所以，我做了这个

Private Sub Button2_Click_1(sender As Object, e As EventArgs) Handles cmdGroupRepeat.Click
    startAndStopClickingButton(sender, Async Sub()
                                           Await finRepeatOrderingAsync() ' this one never end
                                           Dim b = 1 'a breakpoint here
                                       End Sub)
End Sub

现在，dim b=1从未被调用。但是，stopClickingButton被过早调用。为什么

我应该如何改变程序来实现这一点

我试过了

Private Sub Button2_Click_1(sender As Object, e As EventArgs) Handles cmdGroupRepeat.Click
    startAndStopClickingButton(sender, Async Function() As Task
                                           Await finRepeatOrderingAsync() ' this one never end
                                           Dim b = 1
                                       End Function)
End Sub

Public Async Function startAndStopClickingButton2(ByVal sender As Object, ByVal SomeSub As System.Func(Of Task)) As Task
    startClickingButton(sender)
    Await SomeSub.Invoke()
    stopClickingButton(sender)
End Function

我得到一个编译器警告

严重性代码说明项目文件行抑制状态 警告BC42359此异步函数返回的任务将被删除，其中的任何异常都将被忽略。考虑将其更改为异步子，从而传播其异常。nicehash2 H:\business\shared\Dropbox\vb.net\nicehashform.vb 60 Active

尝试以下操作：

Public Async Function startAndStopClickingButton(ByVal sender As Object, ByVal SomeSub As System.Func(Of Task)) As Task
    startClickingButton(sender)
    Await SomeSub.Invoke()
    stopClickingButton(sender)
End Function

Private Async Sub Button2_Click_1(sender As Object, e As EventArgs) Handles cmdGroupRepeat.Click
    Await startAndStopClickingButton(sender, Async Function() As Task
                                           Await finRepeatOrderingAsync()
                                           Dim b = 1
                                       End Sub)
End Sub

---

为什么使用invoke而不是Task.run？你可以试试

Public Async Sub startAndStopClickingButton(ByVal sender As Object, ByVal SomeSub As System.Action)
    startClickingButton(sender)
    Await Task.Run(SomeSub) 
    stopClickingButton(sender)
End Sub

这个代码成功了

Private Async Sub RepeatTheWholeThing_Click_1(sender As Object, e As EventArgs) Handles cmdGroupRepeat.Click
    Await startAndStopClickingButton2(sender, Async Function() As Task
                                                  Await finRepeatOrderingAsync() ' this one never end
                                                  Dim b = 1
                                              End Function)
End Sub

Public Async Function startAndStopClickingButton2(ByVal sender As Object, ByVal SomeSub As System.Func(Of Task)) As Task
    startClickingButton(sender)
    Await SomeSub.Invoke()
    stopClickingButton(sender)
End Function

处理程序本身需要是异步的。然后开始和停止单击按钮也需要是异步的。与保罗的回答唯一不同的是，我等待开始并停止点击按钮2

要了解这是如何工作的，我们需要看到等待并没有真正阻止。它返回给调用者。完成

等待SomeSub.Invoke（）

后，事件处理程序将运行并执行stopClickingButton（发送方）

---

如果有更好的解决方案。我想知道处理程序是否必须是异步的，或者是否真的需要更改startAndStopClickingButton。若然，原因为何？那将是另一个问题。

我收到一个编译器警告。什么编译器警告？我忘了。但是想想看。startAndStopClickingButton是一个返回任务的异步函数。应该等着吧？但不需要。只需调用异步函数而不等待。