再问下GDI+的怪现象

Question

用GraphicsPaht画一个园，Graphics填充这个园，用一个按钮来执行Invalidate()，怪现象产生了，点一下圆消失，再点一下又能出来，如此反复，不想让它消失，请教解决方案

Answer 1

重写你的OnPaint，绘图的代码放这里面。

Answer 2

还是一样，直接填充的图形就没有这个问题，通过Path填充的就不对

Answer 3

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using ControlsDraw;namespace frmDraw
{
    public partial class Form1 : Form
    {
        ToolTip tip = new ToolTip();
        LableEx lblex = new LableEx("I am LableEx");
        RectangleEx rectex = new RectangleEx("I am Rect");
        EllipseEx ellex = new EllipseEx("I am Ellipse");
        CheckBoxEx chkex = new CheckBoxEx("I am CheckBox");
        EntityList elist = new EntityList();        int X;
        int Y;
        public Form1()
        {
            InitializeComponent();
            SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
        }        private void Form1_Load(object sender, EventArgs e)
        {
            lblex.StartPoint = new Point(200, 10);
            elist.Add(lblex);
            elist.Add(rectex);
            elist.Add(ellex);
            elist.Add(chkex);
        }        private void Form1_MouseMove(object sender, MouseEventArgs e)
        {
            X = e.X;
            Y = e.Y;
            foreach (EntityBase eb in elist)
            {
                if (eb.Contains(X, Y))
                {
                    tip.Show(eb.Name, this);
                    return;
                }
            }
            tip.Hide(this);
        }        private void Form1_MouseHover(object sender, EventArgs e)
        {        }        private void button1_Click(object sender, EventArgs e)
        {
            //lblex.SetProperty();
            Invalidate();
        }        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            lblex.DrawEntity(e);
            rectex.DrawEntity(e);
            ellex.DrawEntity(e);
            chkex.DrawEntity(e);
        }    }
}//画圆形的类
public class EllipseEx : EntityBase
    {
        GraphicsPath gp = new GraphicsPath();        public EllipseEx(string name)
            : base()
        {
            
            this.Name = name;
            this.StartPoint = new Point(120, 100);
            this.Size = new Size(30, 30);
        }        public override void DrawEntity(PaintEventArgs e)
        {
            using (brush = new SolidBrush(Color.Red))
            {
                g = e.Graphics;
                gp.AddEllipse(Rect);
                g.FillPath(brush, gp);
            }
        }        public override bool Contains(int X, int Y)
        {
            return gp.IsVisible(X, Y);
        }        public override void SetProperty()
        {
            throw new NotImplementedException();
        }
    }