如何在VB.NET中停止异步等待？

本文介绍了如何在VB.NET中停止异步等待？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我在单击button1时调用的表单中有 async await 方法。当我点击button2时如何停止 async await ？ 我尝试过的事情：

I have async await method in my form that I called when button1 is clicked. How do I stop the async await when I click button2? What I have tried:

Private Async Sub Flash() While True Await Task.Delay(100) Label1.Visible = Not Label1.Visible End While End Sub

以上代码是我的 Async Await 方法

推荐答案

使用取消关注源 [ ^ ]和取消提示 [ ^ ]： Use a CancellationTokenSource[^] and a CancellationToken[^]: Private _cts As CancellationTokenSource Private Async Function Flash(ByVal token As CancellationToken) As Task While Not token.IsCancellationRequested Await Task.Delay(100, token) Label1.Visible = Not Label1.Visible End While End Function Private Async Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Dim newSource As New CancellationTokenSource() Dim oldSource As CancellationTokenSource = Interlocked.Exchange(_cts, newSource) If oldSource IsNot Nothing Then oldSource.Cancel() button1.Enabled = False button2.Enabled = True Try Await Flash(newSource.Token) Finally Interlocked.Exchange(_cts, Nothing) button2.Enabled = False button1.Enabled = True End Try End Sub Private Sub button2_Click(ByVal sender As Object, ByVal e As EventArgs) Dim cts As CancellationTokenSource = Interlocked.Exchange(_cts, Nothing) If cts IsNot Nothing Then cts.Cancel() End Sub