private void button1_Click(object sender, EventArgs e){//创建画布Graphics g = this.CreateGraphics();//设置画笔颜色 画笔宽度Pen redPen = new Pen(Color.Red, 3);//绘制两个端点 Point startPoint = new Point(10, 10);Point endPoint = new Point(100, 200);//用笔和端点绘制直线
            g.DrawLine(redPen, startPoint, endPoint);}private void button2_Click(object sender, EventArgs e){Graphics g = this.CreateGraphics();Pen bluePen = new Pen(Color.Blue,5);g.DrawLine(bluePen,270,10,150,200);}private void button3_Click(object sender, EventArgs e){//曲线Graphics g = this.CreateGraphics();Pen pen1 = new Pen(Color.Blue,3);Point[] points1 ={new Point(20,190),new Point(60,50),new Point(100,180),new Point(140,60),new Point(180,170),new Point(220,70),new Point(260,160)};//绘制一条弯度为0.5的开口曲线//tension范围为 0.0-1.0f g.DrawCurve(pen1, points1,0.5f);Pen pen2 = new Pen(Color.Red,3);Point[] points2 ={new Point(40,370),new Point(80,230),new Point(120,360),new Point(160,240),new Point(200,350),new Point(240,250),new Point(280,340)};//绘制弯曲度为0.9f的封闭曲线g.DrawClosedCurve(pen2, points2, 0.9f,FillMode.Winding);}private void button4_Click(object sender, EventArgs e){//绘制矩形Graphics g = this.CreateGraphics();Pen GreenPen = new Pen(Color.Green,3);Rectangle rect = new Rectangle(330,10,60,80);g.DrawRectangle(GreenPen,rect);}private void button5_Click(object sender, EventArgs e){//椭圆Graphics g = this.CreateGraphics();Pen purplePen = new Pen(Color.Purple,3);Rectangle rect = new Rectangle(330,130,120,60);g.DrawEllipse(purplePen,rect);}private void button6_Click(object sender, EventArgs e){//绘制圆弧Graphics g = this.CreateGraphics();Pen redPen = new Pen(Color.DarkRed,5);Rectangle rect = new Rectangle(430,30,220,110);g.DrawArc(redPen,rect,120, 220);}