Question

我在windows phone中有这样的代码

private void btnrun_Click(object sender, RoutedEventArgs e)
{
    t = 0;
    Start_timer();
}

public void Start_timer()
{
    timer2 = new DispatcherTimer();
    timer2.Tick += timer_Tick2;
    timer2.Interval = new TimeSpan(0, 0, 0, 0, 1000);
    timer2.Start();
}

void timer_Tick2(object sender, object e)
{
    t++;
    txttime.Text = t.ToString();
}

首次使用时，显示从1,2,3,4开始......但是当你再次点击时，它从2,4,6开始....再次点击，显示屏3,6 ...... 有没有办法让它在单击1,2,3,4按钮时运行显示器？谢谢！

Answer 1

使用Stop()方法在每次点击之前停止计时器，然后再次运行。

private void btnrun_Click(object sender, RoutedEventArgs e)
        {
            t = 0;
            timer2.Stop();
            Start_timer();
        }

每个计时器在同一Tick回调中注册：

timer2.Tick += timer_Tick2;

所以这就是问题的原因。

Answer 2

尝试这样的事情：

private void btnrun_Click(object sender, RoutedEventArgs e)
{
    t = 0;
    Start_timer();
}

public void Start_timer()
{
    if (timer2 != null)
    {
        timer2 -= timer_Tick2; // unassigns the event handler
        timer2.Stop(); // stops the timer
    }
    timer2 = new DispatcherTimer();
    timer2.Tick += timer_Tick2;
    timer2.Interval = new TimeSpan(0, 0, 0, 0, 1000);
    timer2.Start();
}

void timer_Tick2(object sender, object e)
{
    t++;
    txttime.Text = t.ToString();
}

编辑：如果您只想启动计时器一次，可以将其缩小为：

private void btnrun_Click(object sender, RoutedEventArgs e)
{
    t = 0;
    if (timer2 == null)
        Start_timer();
}

public void Start_timer()
{
    timer2 = new DispatcherTimer();
    timer2.Tick += timer_Tick2;
    timer2.Interval = new TimeSpan(0, 0, 0, 0, 1000);
    timer2.Start();
}

void timer_Tick2(object sender, object e)
{
    t++;
    txttime.Text = t.ToString();
}

Windows手机中的计时器

2 个答案: