How can I catch both single-click and double-click events on WPF FrameworkElement?

Question

I can catch a single-click on a TextBlock like this:

private void TextBlock_MouseDown(object sender, MouseButtonEventArgs e)
{
    MessageBox.Show("you single-clicked");
}

I can catch a double-click on a TextBlock like this:

private void TextBlock_MouseDown(object sender, MouseButtonEventArgs e)
{
    if (e.LeftButton == MouseButtonState.Pressed)
    {
        if (e.ClickCount == 2)
        {
            MessageBox.Show("you double-clicked");
        }
    }
}

But how do I catch them both on a single TextBlock and differentiate between the two?

Answer 1

You need to fire the event after the click sequence is over... when is that? I suggest using a timer. The MouseDown event would reset it and increase the click count. When timer interval elapses it makes the call to evaluate the click count.

    private System.Timers.Timer ClickTimer;
    private int ClickCounter;

    public MyView()
    {
        ClickTimer = new Timer(300);
        ClickTimer.Elapsed += new ElapsedEventHandler(EvaluateClicks);
        InitializeComponent();
    }

    private void TextBlock_MouseDown(object sender, MouseButtonEventArgs e)
    {
        ClickTimer.Stop();
        ClickCounter++;
        ClickTimer.Start();
    }

    private void EvaluateClicks(object source, ElapsedEventArgs e)
    {
        ClickTimer.Stop();
        // Evaluate ClickCounter here
        ClickCounter = 0;
    }

Cheers!

Answer 2

If you need to detect the difference, I suggest you use a control such as Label that does the work for you:

label.MouseDown += delegate(object sender, MouseEventArgs e)
{
    if (e.ClickCount == 1)
    {
        // single click
    }
};

label.MouseDoubleClick += delegate
{
    // double click
};

EDIT: My advice was following from documentation on MSDN:

The Control class defines the PreviewMouseDoubleClick and MouseDoubleClick events, but not corresponding single-click events. To see if the user has clicked the control once, handle the MouseDown event (or one of its counterparts) and check whether the ClickCount property value is 1.

However, doing so will give you a single click notification even if the user single clicks.

Answer 3

You must use a timer to differentiate between the two. Add a timer to your form in the GUI (easiest that way - it will automatically handle disposing etc...). In my example, the timer is called clickTimer.

private bool mSingleClick;

private void TextBlock_MouseUp(object sender, MouseButtonEventArgs e)
{

    if (e.Button == MouseButtons.Left)
    {
        if (e.ClickCount < 2)
        {
            mSingleClick = true;
            clickTimer.Interval = System.Windows.Forms.SystemInformation.DoubleClickTime;
            clickTimer.Start();
        }
        else if (e.ClickCount == 2)
        {
            clickTimer.Stop();
            mSingleClick = false;
            MessageBox.Show("you double-clicked");
        }
    }
}

private void clickTimer_Tick(object sender, EventArgs e)
{
    if (mSingleClick)
    {
        clickTimer.Stop();
        mSingleClick = false;
        MessageBox.Show("you single-clicked");
    }
}