画图

//矩形按钮点击事件
        private void button1_Click(object sender, EventArgs e)
        {
            //创建一个画板
                        //画板创建在本窗体上
            Graphics g = this.CreateGraphics();
            //创建画笔
            Pen p = new Pen(Color.Red, 5);
            //在画板上画一个矩形
            g.DrawRectangle(p,30,20,100,50);
        }
//实心矩形按钮
        private void button2_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            //创建刷子
            Brush b = Brushes.Red;
            g.FillRectangle(b,160,20,100,50);
        }
//画直线
        private void button3_Click(object sender, EventArgs e)
        {
            //把本窗体作为画板
            Graphics g = this.CreateGraphics();
            //创建画笔
            Pen p = new Pen(Color.Yellow,3);
            //在画板上画直线
            g.DrawLine(p,300,50,400,50);
        }
//画圆形
        private void button4_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            Pen p = new Pen(Color.Red,5);
            g.DrawEllipse(p,30,160,50,50);
        }
//实心圆
        private void button5_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            Brush b = Brushes.Red;
            g.FillEllipse(b,155,160,50,50);
        }
//清画板
        private void button6_Click(object sender, EventArgs e)
        {
            //逻辑：重新给窗体创建一个白色的画板
            //Graphics g = this.CreateGraphics();
            //g.Clear(Color.White);
            this.Refresh();//重置this，重置本窗体
        }
//画字符串
        private void button7_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            Brush b = Brushes.Red;
            g.DrawString("陈丝丝",new Font("黑体",50),b,50,50);
        }