C＃customcontrol OnMouseDown - Y位置总是出错

Question

I am struggling in a project on Windows Mobile 6.5. I am writing a custom-controls that can plot lines of where the user has clicked on the custom-controls.

I am facing a problem that the OnMouseDown(MouseEventArgs e) is not returning correct eY (Y position of clicked location). Anyone please help! I have spent few hours on this issue, but still cannot figure what's wrong. (I think I am in the wrong direction)

Here is what the application looks like:

When I tried to run in a WM6.5 emulator, the OnMouseDown(MouseEventArgs e) always return wrong Y position (It returns Y location minus some values). For example: I clicked on the center of the control for the first click, but obviously the eY is not at the center.

Here is the code spinet:

protected override void OnPaint(PaintEventArgs pe)
    {

        Graphics g = pe.Graphics;

        Pen pen_black = new Pen(Color.Black);
        g.DrawLine(pen_black, 0, 0, this.Width, 0);
        g.DrawLine(pen_black, 0, this.Height - 1, this.Width, this.Height - 1);
        g.DrawLine(pen_black, 0, 0, 0, this.Height);
        g.DrawLine(pen_black, this.Width - 1, 0, this.Width - 1, this.Height);

        // draw center cross
        g.DrawLine(pen_black, this.Width / 2, this.Height / 2 + 10, this.Width / 2, this.Height / 2 - 10);
        g.DrawLine(pen_black, this.Width / 2 + 10, this.Height / 2, this.Width / 2 - 10, this.Height / 2);


        // draw lines between all mouse down point
        if (pointCount > 0)
        {
            Pen pen_red = new Pen(Color.Red);

            for (int i = 0; i < pointCount - 1; i++)
            {
                g.DrawLine(pen_red, lineList[i].X, lineList[i].Y, lineList[i + 1].X, lineList[i + 1].Y);
            }
        }

            base.OnPaint(pe);
    }

    protected override void OnMouseDown(MouseEventArgs e)
    {
        // Put the last point to array            
        lineList[pointCount] = new Point(e.X, e.Y);

        pointCount++;
    }

Here is the source code of my custom-controls: Download here Thanks!

Answer 1

This may sound crazy, and might even be better as a comment if it were not actually a possible solution:

Go into your system settings and configure your screen.

Settings > System Tab > Screen > Align Screen

Answer 2

The Y value is most likely the screen coordinates, not the coordinates within the rectangle you are drawing in. I think you'll need to take into account the taskbar height.

It's been a long time since I worked with WM, but I remember having similar issues when capturing points via MouseEventArgs.