Graphics基本用法

 

   //使用PaintEventArgs 参数创建Graphics对象
        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            e.Graphics.FillRectangle(new SolidBrush(Color.Red), 10, 20, 13, 7);
        }


        private void button1_Click(object sender, EventArgs e)
        {
            Graphics graph;

            //使用窗口句柄创建Graphics
            graph = Graphics.FromHwnd(this.Handle);
            graph.FillRectangle(new SolidBrush(Color.Blue), 30, 20, 13, 7);

            //使用控件句柄创建Graphics
            graph = Graphics.FromHwnd(this.pictureBox1.Handle);
            graph.FillRectangle(new SolidBrush(Color.Red ), 30, 20, 13, 7);

            //创建梯度
            System.Drawing.Drawing2D.LinearGradientBrush lineGrBrush;
            graph = Graphics.FromHwnd(this.Handle);
            lineGrBrush = new System.Drawing.Drawing2D.LinearGradientBrush(
               new Point(10, 30),
               new Point(30, 40), 
               Color.FromArgb(255, 255, 0, 0),
               Color.FromArgb (255,0,0,255));
            graph.FillRectangle(lineGrBrush, 10, 30, 20, 10);

            //路径梯度
            Rectangle rectSquare;
            System.Drawing.Drawing2D.GraphicsPath graphPath;
            System.Drawing.Drawing2D.PathGradientBrush brushSquare;

            graph = Graphics.FromHwnd(this.Handle);
            graphPath = new System.Drawing.Drawing2D.GraphicsPath();
            rectSquare = new Rectangle(50, 20, 23, 27);
            graphPath.AddRectangle(rectSquare);
            brushSquare = new System.Drawing.Drawing2D.PathGradientBrush(graphPath);
            brushSquare.CenterColor = Color.FromArgb(255, 0, 255, 0);
            brushSquare.SurroundColors = new Color[] { Color.FromArgb(255, 0, 0, 255) };
            graph.FillRectangle(brushSquare, rectSquare);

            //一定要注意释放资源....
            graph.Dispose();
        }