GDI

绘图GDI

准备

        Graphics g1;//封装到g1中  
        Graphics g = this.CreateGraphics();
        Pen pen;//画笔（线）
        Font font = new Font("宋体", 10, FontStyle.Bold);//画文字，10磅
        Brush brushred = new SolidBrush(Color.Red);//实心（SolidBrush）矩形框（填充）
       Rectangle rect1=new Rectangle(20,120,10,160);//起始位置，宽高  

画

 g4.DrawRectangle(pen, Stack4CurrentX, Stack4CurrentY, dx, dy);//画矩形框，笔，起始点，长宽
 g4.DrawString(CurrentPage, font, brush, Stack4CurrentX + 4, Stack4CurrentY + 4);//画字符串，字体，填充，起始位置                 

• 左上角坐标原点，左手系
• color：封装了颜色对象：
  三种办法:FromArgb:通过三原色构建color对象
  FromKnownColor:通过已知颜色构建color对象
  FromName：通过颜色名称构建（常用）

Color t1=Color.Black;
Color t2=Color.FromArgb(0,0,0);//红绿蓝，000黑
Color t3=Color.FromName("Black");

• size
  尺寸，可加减

• point
  点
  pointF(浮点型)

• Rectangle
  Rectangle(整数)
  RectangleleF(浮点数)

绘图深入应用函数图

以点绘图，用点表示函数

 private void button1_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            PointF[] cur1 = new PointF[150];
            for(int i=0;i<cur1.Length;i++)
            {
                double x = (double)i / 5;
                double y = Math.Sin(x) * Math.Cos(3 * x);
                cur1[i] = new PointF((float)i, (float)(y * 10 + 100));

            }
            g.DrawLines(Pens.Blue, cur1);

        }

• Transfrom 坐标变换，本质是矩阵
  给你一个坐标，乘上这个矩阵，得到心得坐标
• 通过三个变换得到
  g.ScaleTransform(0.8F, 0.8F);//比例变换
  g.TranslateTransform(x / 2, y / 2 + 20);//平移变换
  g.RotateTransform(10);//旋转变换
  

 private void button2_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            g.FillRectangle(Brushes.White, 0, 0, Width, Height);
            float x = g.VisibleClipBounds.Width;
            float y = g.VisibleClipBounds.Height;
            PointF[] pts = { new PointF(0, 0), new PointF(x / 2, 0), new PointF(x / 2, y / 2), new PointF(0, y / 2) };
            Pen pen = new Pen(Color.Blue, 1.0F);
            g.ScaleTransform(0.8F, 0.8F);
            g.TranslateTransform(x / 2, y / 2 + 20);
            for (int i = 0; i < 36; i++)
            {
                g.DrawBeziers(pen, pts);
                g.DrawRectangle(pen, -x / 12, -y / 12, x / 6, y / 6);
                g.DrawEllipse(pen, -x / 4, -y / 3, x / 2, y * 2 / 3);
                g.RotateTransform(10);
            }
        }

PATH

渐变填充

  private void button3_Click(object sender, EventArgs se)
        {
            GraphicsPath gp = new GraphicsPath(FillMode.Winding);
            gp.AddString(//字的轮廓作为路径
            "字体轮廓",//文字
            new FontFamily("方正舒体"),
             (int)FontStyle.Regular,
             180,
            new PointF(10, 20),//位置
            new StringFormat());
            //一个brush，这个brush是一个线性渐变的刷子
            Brush brush = new LinearGradientBrush(
            new PointF(0, 0), new PointF(Width, Height),
            Color.Blue, Color.Red);
            Graphics g = this.CreateGraphics();
            g.DrawPath(Pens.Black, gp);
            g.FillPath(brush, gp);
        }