使面板可拖动

Question

I am creating a "cropping tool", and i need to make a panel that contains 2 buttons draggable.

Until now i've tried something like this, but the change location event happens only when i click the right button of the mouse...

this.MouseDown += new MouseEventHandler(onRightClickMouse);
private void onRightClickMouse(object sender, MouseEventArgs e)
{
      if (e.Button == MouseButtons.Right)
      {
            Point localMouseClickPoint = new Point(e.X, e.Y);
            panel1.Location = localMouseClickPoint;
      }
}

My question: How can i make that panel draggable in my form?(I mean click on the panel then drag it to a location).

Answer 1

Try something like this:

delegate void updatePanelCallback();
panel1.MouseDown += new MouseEventHandler(onMouseDown);
panel1.MouseUp += new MouseEventHandler(onMouseUp);
System.Timers.Timer runTimer = new System.Timers.Timer(100);
runTimer.Elapsed += new ElapsedEventHandler(onTimerElapsed);
private void onMouseDown(object sender, MouseEventArgs e)
{
    if (e.Button != MouseButtons.Right)
    {
        return;
    }
    runTimer.Enabled = false;
}
private void onMouseUp(object sender, MouseEventArgs e)
{
    runTimer.Enabled = false;
}
public void updatePanelLocation()
{
    if (this.InvokeRequired)
    {
        this.Invoke(new updatePanelCallback(updatePanelLocation), new object[] {});
    }
    else
    {
        Cursor curs = new Cursor(Cursor.Current.Handle);
        panel1.Location = curs.Position;
    }
}
private void onTimerElapsed(object source, ElapsedEventArgs e)
{
    updatePanelLocation();
}

Answer 2

您可以分两步进行尝试，准备对MouseDown事件的操作并在MouseUp 。