Question

I am attempting to just draw basic shapes to a panel on my form. so far nothing happens and I dont know why. This method is called in the constructor of my form.

private void doGraphics()
    {
        Pen p = new Pen(Color.Black);//draws wire frame Shapes
        SolidBrush sb = new SolidBrush(Color.Yellow);//draws filled Shapes
        Graphics g = panel1.CreateGraphics();


        Point[] pointArray = { new Point(100, 20), new Point(100, 0), new Point(120, 0), new Point(120, 20) };
        g.FillPolygon(sb, pointArray);
        g.DrawPolygon(p, pointArray);
    }

Any suggestions would be great!

Answer 1

You need to register to the Paint event of the panel and use the graphics object that comes with the arguments:

In constructor:

panel1.Paint += new PaintEventHandler(panel1_Paint);

The handler itself:

void panel1_Paint(object sender, PaintEventArgs e) {
{
        Pen p = new Pen(Color.Black);//draws wire frame Shapes
        SolidBrush sb = new SolidBrush(Color.Yellow);//draws filled Shapes
        Graphics g = e.Graphics; // From Arguments


        Point[] pointArray = { new Point(100, 20), new Point(100, 0), new Point(120, 0), new Point(120, 20) };
        g.FillPolygon(sb, pointArray);
        g.DrawPolygon(p, pointArray);
}