How to capture mousemove events beneath child controls

Question

I am trying to handle a mouseclick event on a particular form that should fire if the mouse cursor falls between a set of coordinates - lets say a square.

I understa

Answer 1

I know I'm a bit late to the punch, but I was having troubles with this earlier today when using a Panel as a title bar. I had a label to display some text, a picturebox and a few buttons all nested within the Panel, but I needed to trap the MouseMove event regardless.

What I decided to do was implement a recursive method handler to do this, as I only had 1 level of nested controls, this may not scale overly well when you start approaching ridiculous levels of nesting.

Here's how I did it:

    protected virtual void NestedControl_Mousemove(object sender, MouseEventArgs e)
    {
        Control current = sender as Control;
        //you will need to edit this to identify the true parent of your top-level control. As I was writing a custom UserControl, "this" was my title-bar's parent.
        if (current.Parent != this) 
        {
            // Reconstruct the args to get a correct X/Y value.
            // you can ignore this if you never need to get e.X/e.Y accurately.
            MouseEventArgs newArgs = new MouseEventArgs
            (
                e.Button, 
                e.Clicks, 
                e.X + current.Location.X, 
                e.Y + current.Location.Y, 
                e.Delta
            );
            NestedControl_Mousemove(current.Parent, newArgs);
        }
        else
        {
            // My "true" MouseMove handler, called at last.
            TitlebarMouseMove(current, e);
        }
    }

    //helper method to basically just ensure all the child controls subscribe to the NestedControl_MouseMove event.
    protected virtual void AddNestedMouseHandler(Control root, MouseEventHandler nestedHandler)
    {
        root.MouseMove += new MouseEventHandler(nestedHandler);
        if (root.Controls.Count > 0)
            foreach (Control c in root.Controls)
                AddNestedMouseHandler(c, nestedHandler);
    }

And then to set it up is relatively simple:

Define your "true" handler:

    protected virtual void TitlebarMouseMove(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            this.Text = string.Format("({0}, {1})", e.X, e.Y);
        }
    }

And then set up the controls event subscribers:

//pnlDisplay is my title bar panel.
AddNestedMouseHandler(pnlDisplay, NestedControl_Mousemove);

Relatively simple to use, and I can vouch for the fact it works :)