Tooltips won't show second time form is created.

Question

I have a dialog box with controls that is popped up and when a control is moused over the controls a tooltip is displayed. However, if I close the box then re-display it no tooltips will work. Here is a portion of my code. I am initializing tooltipOn when the form is loaded to null. I have done a trace and tooltip1.Show() does get called the second time it simply never displays. Any idea why?

private void Panel1_MouseMove(object sender, MouseEventArgs e)
{
    Control ctrl = null;

    if (sender == Panel1)
        ctrl = ((Control)sender).GetChildAtPoint(e.Location);
    else
        ctrl = (Control)sender;

    if (ctrl != null)
    {
        if (tooltipOn != ctrl)
        {
            toolTip1.Show(toolTip1.GetToolTip(ctrl), ctrl, ctrl.Width / 2, ctrl.Height / 2);
            tooltipOn = ctrl;
        }
    }
    else
    {
        toolTip1.Hide(this);
        tooltipOn = null;
    }
}

Answer 1

Maybe because you can't show the tooltip twice on two different controls?

Try this inside your if statement:

if (tooltipOn != ctrl)
{
    //your moving the tooltip to a different control, 
    //hide it from the other first.
    if (tooltipOn != null)
        toolTip1.Hide(tooltipOn);  

    toolTip1.Show(
        toolTip1.GetToolTip(ctrl), ctrl, ctrl.Width / 2, ctrl.Height / 2
    );

    tooltipOn = ctrl;
}

If that doesn't work I would try newing up an entirely different tool tip altogether to make sure each control get's their own during the event.

Answer 2

Ok so...after playing around the solution to this problem for anyone in the future who finds this post useful is posted below. Why this is necessary is beyond me.

Change

toolTip1.Show(toolTip1.GetToolTip(ctrl), ctrl, ctrl.Width / 2, ctrl.Height / 2);

To

toolTip1.Show(toolTip1.GetToolTip(ctrl), ctrl, ctrl.Width / 2, ctrl.Height / 2);
toolTip1.Hide(ctrl);
toolTip1.Show(toolTip1.GetToolTip(ctrl), ctrl, ctrl.Width / 2, ctrl.Height / 2);