不睡觉就等着？

Question

我要做的是启动一个函数，然后将bool改为false，等一下再将其变为true。但是，我想在不需要等待功能的情况下完成它，我该如何做呢？

我只能使用视觉C# 2010快车。

这是有问题的代码。我尝试接收用户输入(例如，右箭头)并相应移动，但在字符移动时不允许进一步输入。

        x = Test.Location.X;
        y = Test.Location.Y;
        if (direction == "right") 
        {
            for (int i = 0; i < 32; i++)
            {
                x++;
                Test.Location = new Point(x, y);
                Thread.Sleep(31);
            }
        }
    }

    private void Form1_KeyDown(object sender, KeyEventArgs e)
    {
        int xmax = Screen.PrimaryScreen.Bounds.Width - 32;
        int ymax = Screen.PrimaryScreen.Bounds.Height - 32;
        if (e.KeyCode == Keys.Right && x < xmax) direction = "right";
        else if (e.KeyCode == Keys.Left && x > 0) direction = "left";
        else if (e.KeyCode == Keys.Up && y > 0) direction = "up";
        else if (e.KeyCode == Keys.Down && y < ymax) direction = "down";

        if (moveAllowed)
        {
            moveAllowed = false;
            Movement();
        }
        moveAllowed = true;  
    }

Answer 1

使用Task.Delay

Task.Delay(1000).ContinueWith((t) => Console.WriteLine("I'm done"));

或

await Task.Delay(1000);
Console.WriteLine("I'm done");

对于旧的框架，您可以使用以下方法：

var timer = new System.Timers.Timer(1000);
timer.Elapsed += delegate { Console.WriteLine("I'm done"); };
timer.AutoReset = false;
timer.Start();

根据问题中的描述，示例：

class SimpleClass
{
    public bool Flag { get; set; }

    public void function()
    {
        Flag = false;
        var timer = new System.Timers.Timer(1000);
        timer.Elapsed += (src, args) => { Flag = true; Console.WriteLine("I'm done"); };
        timer.AutoReset = false;
        timer.Start();
    }
}

Answer 2

我意识到答案已经被接受了，我很喜欢ixSci的回答，他建议使用Timer对象来实现OP的目标。

但是，使用System.Timers.Timer特别引入了线程处理注意事项。为了确保在这种情况下的正确性，需要更多代码来正确地同步布尔标志值。基本上，在读取或写入标志的任何地方，代码区域都需要在其周围定义一个锁语句。

它必须看起来像这样：

private final object flagLock = new object();
private bool moveAllowed = true;
private System.Timers.Timer timer = new System.Timers.Timer();

public Form1()
{
    this.timer.Interval = 1000;
    this.timer.AutoReset = false;
    this.timer.Elapsed += (s, e) =>
    {
        // this DOES NOT run on the UI thread, so locking IS necessary to ensure correct behavior.
        this.timer.Stop();
        lock (this.flagLock) {
            this.moveAllowed = true;
        }
    };
}

// The code in this event handler runs on the UI thread.
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
    // Locking is necessary here too.
    lock (this.flagLock) {
        if (this.moveAllowed)
        {
            this.moveAllowed = false;
            Movement();
            this.timer.Start(); // wait 1 second to reset this.moveAllowed to true.
        }
    }
}

或者，为了避免考虑线程，OP也许可以考虑使用不同风格的Timer类。即：System.Windows.Forms.Timer.这样，布尔标志将始终在UI线程上读取/写入，并且不需要任何类型的额外锁定来确保正确性。

在本例中，代码如下所示：

private bool moveAllowed = true;
private System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();

public Form1()
{
    this.timer.Interval = 1000;
    this.timer.Tick += (s, e) =>
    {
        // this runs on the UI thread, so no locking necessary.
        this.timer.Stop(); // this call is necessary, because unlike System.Timers.Timer, there is no AutoReset property to do it automatically.
        this.moveAllowed = true;
    };
}

// The code in this event handler runs on the UI thread.
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
    if (this.moveAllowed)
    {
        this.moveAllowed = false;
        Movement();
        this.timer.Start(); // wait 1 second to reset this.moveAllowed to true.
    }
}