绘图

 　　　　// 新建窗体 (.cs)
        // 重写OnPaint事件

        //1、清除绘画面
        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    Graphics g = e.Graphics;//绘制图形的对象
        //    g.Clear(Color.White);
        //    g.Dispose();
        //}

        //2、绘制线条
        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    Graphics g = e.Graphics;//绘制图形的对象
        //    //画一条直线
        //    Pen pen = new Pen(Color.Red);//钢笔绘制对象
        //    Point p1 = new Point(50, 50);
        //    Point p2 = new Point(150, 50);
        //    g.DrawLine(pen, p1, p2);
        //    //画宫格
        //    int y = 100;
        //    for (int i = 0; i < 5; i++)
        //    {
        //        g.DrawLine(new Pen(Color.Black), new Point(100, y), new Point(200, y));
        //        y += 20;
        //    }
        //    int x = 100;
        //    for (int i = 0; i < 5; i++)
        //    {
        //        g.DrawLine(new Pen(Color.Black), new Point(x, 100), new Point(x, 100 + 80));
        //        x += 25;
        //    }
        //    g.Dispose();
        //}

        //3、绘制图形
        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    Graphics g = e.Graphics;//绘制图形的对象
        //    //画矩形
        //    Rectangle rect = new Rectangle(200, 10, 100, 50);
        //    g.DrawRectangle(new Pen(Color.Black), rect);
        //    //画椭圆
        //    g.DrawEllipse(new Pen(Brushes.Black), new Rectangle(50, 50, 100, 50));
        //    //画圆
        //    g.DrawEllipse(new Pen(Brushes.Black), new Rectangle(200, 200, 100, 100));
        //    //画扇形
        //    g.DrawPie(new Pen(Brushes.Black), new Rectangle(10, 200, 100, 100), 0, 45);
        //    //画多边形
        //    Point[] points = new Point[] {
        //                        new Point(300,150),
        //                        new Point(400,150),
        //                        new Point(450,200),
        //                        new Point(250,200)
        //                     };
        //    g.DrawPolygon(new Pen(Color.Black), points);
        //    g.Dispose();
        //}

        //4、填充图形
        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    Graphics g = e.Graphics;//绘制图形的对象
        //    //简单填充
        //    g.FillRectangle(Brushes.Yellow, new Rectangle(100, 100, 50, 20));
        //    //渐变填充
        //    Brush brush = new LinearGradientBrush(new Point(10, 10), new Point(60, 30), Color.Blue, Color.White);
        //    g.FillRectangle(brush, new Rectangle(10, 10, 50, 20));
        //    g.Dispose();
        //}

        //5、绘制路径
        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    Graphics g = e.Graphics;//绘制图形的对象
        //    Point[] points = new Point[] {
        //                        new Point(300,150),
        //                        new Point(400,150),
        //                        new Point(450,200),
        //                        new Point(250,200)
        //                     };
        //    GraphicsPath path = new GraphicsPath(
        //                points, new byte[]{
        //                    (byte)PathPointType.Start,
        //                    (byte)PathPointType.Line,
        //                    (byte)PathPointType.Line,
        //                    (byte)PathPointType.Line
        //            });
        //    g.DrawPath(new Pen(Color.Black), path);
        //    g.Dispose();
        //}

        //6、绘制字符串
        protected override void OnPaint(PaintEventArgs e)
        {
            Graphics g = e.Graphics;//绘制图形的对象
            //普通绘制字符串
            Font font1 = new System.Drawing.Font("楷体_gb2312", 30);
            g.DrawString("abc", font1, Brushes.Red, 100, 100);
            //带格式绘制字符串
            Font font2 = new System.Drawing.Font("宋体", 30);
            RectangleF rect = new RectangleF(200, 200, 100, 50);
            g.DrawRectangle(new Pen(Color.Black), new Rectangle(200, 200, 100, 50));
            StringFormat sf = new StringFormat();//字符串格式对象
            sf.LineAlignment = StringAlignment.Center;//设置垂直方向居中
            sf.Alignment = StringAlignment.Center;//设置水平方向居中
            g.DrawString("abc", font2, Brushes.Red, rect, sf);
            g.Dispose();
        }

        //7、绘制图片
        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    Graphics g = e.Graphics;//绘制图形的对象
        //    //普通绘制
        //    Image image = Image.FromFile("images/mouse.png");//获取图片对象
        //    g.DrawImage(image, new Point(50, 50));
        //    g.Dispose();
        //}

        //8、纹理画笔绘制图片
        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    Graphics g = e.Graphics;//绘制图形的对象
        //    Image image = Image.FromFile("images/mouse.png");//获取图片对象
        //    Brush brush = new TextureBrush(image);//纹理画笔
        //    g.DrawEllipse(new Pen(Color.Black), new Rectangle(10, 10, 500, 500));
        //    g.FillEllipse(brush, new Rectangle(10, 10, 500, 500));
        //    g.Dispose();
        //}

        //9、缓冲画图（先把文本绘制到图像上，完成了所有的绘图操作后，把整个图像绘制到窗口）
        //protected override void OnPaint(PaintEventArgs e)
        //{
        //    Image image = new Bitmap(300, 300);//创建画布对象
        //    //将5根线条绘制在image上
        //    Graphics g = Graphics.FromImage(image);//获取image的绘制对象
        //    int x = 10;
        //    for (int i = 0; i < 5; i++)
        //    {
        //        g.DrawLine(new Pen(Color.Black), new Point(10, 10), new Point(x, 100));
        //        x += 20;
        //    }
        //    //将image绘制到窗体中
        //    e.Graphics.DrawImage(image, new Point(100, 100));
        //}