如何通过按钮单击退出循环 [英] How to make exit from loop by button click

问题描述

我想点击[取消]按钮退出循环。

I want to make exit from loop by clicking [Cancel] button.

我制作了样本测试程序。

I made sample test program.

有太按钮，一个是[开始]，它开始循环，另一个是[取消]，它将变量设置为真，以便退出循环。

There are too buttons, one is [Start], which starts loop and another is [Cancel], which set variable to true in order to make exit from loop.

public partial class Form1 : Form
{
    bool CancelClicked = false;
    public Form1()
    {
        InitializeComponent();
    }

    private void CancelButton_Click(object sender, EventArgs e)
    {
        CancelClicked = true;
    }

    private void StartButton_Click(object sender, EventArgs e)
    {
        do
        {
            Application.DoEvents();
            Thread.Sleep(100);
            if (CancelClicked == true)
            {
                CancelClicked = false;
                MessageBox.Show("exit loop!");
                break;
            }
        } while (true);
    }
}

但是"if（CancelClicked = = = true）"在CancelButton_Click事件中未检测到CancelClicked已更改。

However "if (CancelClicked == true)" doesn't detect CancelClicked is changed in CancelButton_Click event.

如何通过单击[取消]按钮退出循环？

How can I make exit from loop by clicking [Cancel] button?

推荐答案

尝试以下

CancellationTokenSource cTokenSource = new CancellationTokenSource();
private async void button1_Click(object sender, EventArgs e)
{
    cTokenSource = new CancellationTokenSource();
    int i;
    for (i = 0; i < 10000; i++)
    {
        Console.WriteLine("Number: {0}", i);
        await Task.Delay(1);
        if (cTokenSource.IsCancellationRequested)
        {
            break;
        }
    }
}
private void button2_Click(object sender, EventArgs e)
{
    cTokenSource.Cancel();
}

或

CancellationTokenSource cTokenSource = new CancellationTokenSource();
private async void button1_Click(object sender, EventArgs e)
{
    cTokenSource = new CancellationTokenSource();
    int i = 0;
    do
    {
        Console.WriteLine(

" {i}"）;
i + = 1;
await Task.Delay（1）;
if（cTokenSource.IsCancellationRequested）
{
break;
}
} while（true）;
}
private void button2_Click（object sender，EventArgs e）
{
cTokenSource.Cancel（）;
}

"{i}"); i += 1; await Task.Delay(1); if (cTokenSource.IsCancellationRequested) { break; } } while (true); } private void button2_Click(object sender, EventArgs e) { cTokenSource.Cancel(); }

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