WPF响应长按事件

原文:WPF响应长按事件

版权声明：本文为博主原创文章，转载请注明出处。 https://blog.csdn.net/lwwl12/article/details/78983140

思路：MouseDown 时启动一个线程并标记IsMouseDown=True，若MouseUp则修改标记IsMouseDown=False，线程内Sleep 1500ms之后判断IsMouseDown=True则开始响应事件

bool IsLeftMouseDown = false;
private void DataGrid_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    IsLeftMouseDown = true;
    Thread th = new Thread(new ThreadStart(() =>
    {
        Thread.Sleep(1500);  

        if (IsLeftMouseDown)
        {
            MessageBox.Show("长按了1.5秒");
            IsLeftMouseDown = false;
        }
        else
        {
            MessageBox.Show("1.5秒内释放了点击");
        }
    }));
    th.Start();
}  

private void DataGrid_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    IsLeftMouseDown = false;
}  

以上的实现可以解决问题，但是有bug，以下提供更优的解决方案：

        bool IsLeftMouseDown = false;

        bool EntryTouch = false;

        Thread th = null;
        private void DataGrid_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            IsLeftMouseDown = true;

            if (th != null)
            {
                if (th.ThreadState == ThreadState.Running || th.ThreadState == ThreadState.WaitSleepJoin)
                    th.Abort();
            }
            th = new Thread(new ThreadStart(() =>
            {
                Thread.Sleep(1500);

                if (IsLeftMouseDown)
                {
                    EntryTouch = true;

                    MessageBox.Show("长按了1.5秒");
                    IsLeftMouseDown = false;
                }
                else
                {
                    MessageBox.Show("1.5秒内释放了点击");
                }

                EntryTouch = false;

            }));
            th.Start();
        }

        private void DataGrid_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            if(EntryTouch)
            {
                MessageBox.Show("已进入长按事件");
            }

            IsLeftMouseDown = false;
        }