GDI画三角形 画矩形 画圆 画椭圆

        private void test_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            Pen pen = new Pen(Color.Blue, 2);
            Point[] pointsl = 
            {
                new Point(90,40),
                new Point(40,150),
                new Point(140,150)
             };
            e.Graphics.DrawPolygon(pen, pointsl);


            Brush brush = new SolidBrush(Color.Red);
            Point[] points2 = 
            {
                new Point(230,40),
                new Point(180,150),
                new Point(280,150)
             };
            e.Graphics.FillPolygon(brush, points2);
        }

        private void test_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            Pen pen = new Pen(Color.Blue, 2);

            e.Graphics.DrawRectangle(pen, 20, 20, 100, 120);


            Brush brush = new SolidBrush(Color.Red);

            e.Graphics.FillRectangle(brush, 170, 20, 100, 120);
          
        }

        private void test_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            Pen pen = new Pen(Color.Blue, 2);
            e.Graphics.DrawEllipse(pen, 20, 50, 150, 100);
            Brush brush = new SolidBrush(Color.Red);

            e.Graphics.FillEllipse(brush, 200, 50, 100, 100);
          
        }