Creation of rectangle on pointer position

Question

I am trying to create a rectangle which moves with the pointer in order to make it more clear for the user to see on which part of the screen the mouse pointer is. So far I managed to create the rectangle but I have a problem, each movement the pointer makes it is creating a new rectangle but I need to remove the old ones. this means that I only want ONE rectangle which moves around with the mouse pointer. This is my code so far. Could you please help?

PS I already user the clear() method and this.Invalidate();

private void Form1_MouseMove(object sender, MouseEventArgs e)
{
    int posX = e.X;
    int posY = e.Y;

    Graphics g = Graphics.FromHwnd(IntPtr.Zero);

    mouseNewRect = new Rectangle(new Point(posX, posY), new Size(100, 100));

    if (mouseOldRect.X != mouseNewRect.X || mouseOldRect.Y != mouseNewRect.Y)
    {
         mouseOldRect = mouseNewRect;

         g.DrawRectangle(new Pen(Brushes.Chocolate), mouseNewRect);
        // this.Invalidate();
     }
}

Answer 1

Instead of drawing to the form, I would create a custom cursor.

Instructions are available here:

https://msdn.microsoft.com/en-us/library/system.windows.forms.cursor%28v=vs.110%29.aspx

Answer 2

Set Form1 DoubleBuffer property to true .

Use Form1 paint event to draw:

bool drawRect = false;

private void Form1_Paint(object sender, PaintEventArgs e)
{
    if(drawRect)
    {
        e.Graphics.DrawRectangle(new Pen(Brushes.Chocolate), mouseNewRect);
    }
}

private void Form1_MouseMove(object sender, MouseEventArgs e)
{
    if(drawRect == false)
    {
        drawRect = true;
    }

    mouseNewRect = new Rectangle(new Point(e.X, e.Y), new Size(100, 100));

    this.Invalidate();
}

private void Form1_MouseLeave(object sender, EventArgs e)
{
    //This will erase the rectangle when the mouse leaves Form1
    drawRect = false;

    this.Invalidate();
}