窗体工具控件 

如果选纹理 ,需要在ImageList中选择图像(点击添加选择图片路径)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace 画
{
    public partial class Form1 : Form
    {//重写窗体 Form1 的 OnPaint()方法 
        protected override void OnPaint(PaintEventArgs e) {
            //调用基类的 Onpain()方法绘制窗体
            base.OnPaint(e);
            //添加自己的代码绘制图形
            Graphics g = e.Graphics;
            Pen pen = new Pen(Color.Red, 5);
            PointF[] Tpoit = new PointF[] { new PointF(26, 50),new PointF(90, 80),
              new PointF(190, 180), new PointF(26, 50)        };//多边形之三角形
                                                       
            g.DrawEllipse(pen, 20, 30, 230, 80);//椭圆
            g.DrawPolygon(pen, Tpoit);
            g.Dispose();
        }
        public Form1()
        {
            InitializeComponent();
        }

        private void btnDrowLine_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();//创建 Graphics 对象
            Pen pen = new Pen(Color.Red,3);
            Point startpoit = new Point(50, 80);
            Point endpoint = new Point(250, 80);
            g.DrawLine(pen ,startpoit,endpoint);//画直线 
            pen .Dispose();//释放资源
            g.Dispose();

        }

        private void btnClear_Click(object sender, EventArgs e)
        {
            Graphics d = this.CreateGraphics();
            d.Clear(BackColor);
            d.Dispose ();
                               }

        private void tuoyuan_Click(object sender, EventArgs e)
        {
            Graphics g = CreateGraphics();
            SolidBrush brush = new SolidBrush(Color.Green); //画刷 
            g.FillEllipse(brush, 120, 30, 200, 100); //画实心椭圆 
            g.Dispose();
            brush.Dispose();

        }
        
//声明画刷
private Brush brush = new SolidBrush(Color.Red);
        

        private void radioButton1_CheckedChanged(object sender, EventArgs e)//实心
        {
            brush = new SolidBrush(Color.Green); //参数为填充的颜色
        }

        private void radioButton2_CheckedChanged(object sender, EventArgs e)//纹理
        {
            brush = new TextureBrush(imageList1.Images[0]); //参数为填充的图/拖入imageList控件
        }

        private void radioButton3_CheckedChanged(object sender, EventArgs e)//渐变
        {

            Point startPoint = new Point(80, 70);
            Point endPoint = new Point(310, 70);
            brush = new LinearGradientBrush(startPoint, endPoint, Color.Red, Color.Yellow);
        }

        private void radioButton4_CheckedChanged(object sender, EventArgs e)//阴影
        {
            brush = new HatchBrush(HatchStyle.ForwardDiagonal, Color.Red, Color.LightGreen);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Graphics g = CreateGraphics();
            g.FillEllipse(brush, 80, 30, 230, 80);
            g.Dispose();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            //定义路径中的顶点
            Point[] pt = new Point[10];
            pt[0] = new Point(120, 46);
            pt[1] = new Point(156, 46);
            pt[2] = new Point(168, 10);
            pt[3] = new Point(180, 46);
            pt[4] = new Point(214, 46);
            pt[5] = new Point(188, 70);
            pt[6] = new Point(198, 106);
            pt[7] = new Point(168, 82);
            pt[8] = new Point(138, 104);
            pt[9] = new Point(150, 70);
            GraphicsPath path = new GraphicsPath(); //创建路径 
            for (int i = 0; i <= 8; i++)
            {
                path.AddLine(pt[i], pt[i + 1]); //添加线段
            }
            path.CloseFigure(); //闭合起点和终点
            Pen pen = new Pen(Color.Black, 5);
            Graphics g = CreateGraphics();
            SolidBrush brush = new SolidBrush(Color.Blue); //画刷 
            g.FillPath(brush, path);//填充颜色
           g.DrawPath(pen, path);//单绘制路径
            g.Dispose();
            path.Dispose();
        }
    }
}

运行效果: