C#Graphics画图

 public Form1()

        {

            InitializeComponent();

        }



        private void button1_Click(object sender, EventArgs e)

        {

            Graphics g = this.CreateGraphics();//创建GDI对像



            //创建画笔(颜色)

            Pen npen = new Pen(Brushes.Red);



            //创建两个点

            Point n1 = new Point(20, 20);

            Point n2 = new Point(255, 255);



            g.DrawLine(npen, n1, n2);



        }



        private void Form1_Paint(object sender, PaintEventArgs e)

        {

            Graphics g = this.CreateGraphics();//创建GDI对像



            //创建画笔(颜色)

            Pen npen = new Pen(Brushes.Red);



            //创建两个点

            Point n1 = new Point(20, 20);

            Point n2 = new Point(255, 255);



            g.DrawLine(npen, n1, n2);



        }



        private void button2_Click(object sender, EventArgs e)

        {

            Graphics ng = this.CreateGraphics();



            //创建画笔

            Pen npen = new Pen(Brushes.Red);



            Size sz=new System.Drawing.Size(100,100);

            Rectangle res = new Rectangle(new Point(50, 50), sz);



            ng.DrawRectangle(npen, res);

        }



        private void button3_Click(object sender, EventArgs e)

        {

            Graphics g = this.CreateGraphics();



            Pen npen = new Pen(Brushes.Blue);



            Size sz = new System.Drawing.Size(180, 180);



            Rectangle rec = new Rectangle(new Point(150, 150), sz);



            g.DrawPie(npen, rec, -50, -50);

        }



        private void button4_Click(object sender, EventArgs e)

        {

            Graphics g = this.CreateGraphics();



            Pen npen = new Pen(Brushes.Blue);



            g.DrawString("我是中国人", new Font("宋体", 20, FontStyle.Bold), Brushes.Blue, new PointF(29, 29));

        }