C# 之控件重绘（二）

本篇是接着上一篇写的，上一篇只是对按钮的前景色，背景色等做了一些改变，由于按钮的一个重要功能是本篇将涉及到鼠标事件，包括按下、抬起、经过、离开等事件。

修改上一篇的MyButton.cs文件即可：

using System;
using System.Windows;
using System.Windows.Forms;
using System.Drawing;

namespace WindowsFormsApplication1
{
     class MyButton:System.Windows.Forms.Button
    {
        private bool mouseDown = false;
        private bool mouseHover = false;

        public MyButton()
        {
            SetStyle(ControlStyles.UserPaint, true);
            MouseDown += new MouseEventHandler(OnMouseDown);
            MouseUp += new MouseEventHandler(OnMouseUp);
            MouseEnter += new EventHandler(OnMouseEnter);
            MouseLeave += new EventHandler(OnMouseLeave);
            Height = 23;
            Width = 75;
        }
        private void OnMouseDown(object sender, MouseEventArgs e)
        {
            mouseDown = true;
        }
        private void OnMouseUp(object sender, MouseEventArgs e)
        {
            mouseDown = false;
            OnPaint(new PaintEventArgs(CreateGraphics(), ClientRectangle));
        }
        private void OnMouseEnter(object sender, EventArgs e)
        {
            mouseHover = true;
            OnPaint(new PaintEventArgs(CreateGraphics(), ClientRectangle));
        }
        private void OnMouseLeave(object sender, EventArgs e)
        {
            mouseHover = false;
            OnPaint(new PaintEventArgs(CreateGraphics(), ClientRectangle));
        }
        protected override void OnPaint(PaintEventArgs pevent)
        {
            pevent.Graphics.FillRectangle(new SolidBrush(Parent.BackColor),
                pevent.ClipRectangle);
            if (Enabled == false)
            {
                DrawDisableButton(pevent.Graphics);
            }
            else if (mouseDown)
            {
                DrawMouseDownButton(pevent.Graphics);
            }
            else if (mouseHover)
            {
                DrawMouseHoverButton(pevent.Graphics);
            }
            else if (Focused)
            {
                DrawContainFocusButton(pevent.Graphics);
            }
            else
            {
                DrawNormalButton(pevent.Graphics);
            }
                WriteText(pevent.Graphics);
            //base.OnPaint(pevent);
        }

        private void DrawBorder(Graphics g, int state)
        {
            if (state == 1)//draw normal style border
            {
                Pen p = new Pen(SystemColors.ControlLightLight, 2);
                g.DrawLine(p, 1, 1, 1, Height - 2);
                g.DrawLine(p, 1, 1, Width - 2, 1);
                g.DrawLine(p, Width - 1, 2, Width - 1, Height - 2);
                g.DrawLine(p, 2, Height - 1, Width - 2, Height - 1);
            }
            else if (state == 2)//draw hover style border
            {
                Pen p = new Pen(Color.Yellow, 2);
                g.DrawLine(p, 1, 1, 1, Height - 2);
                g.DrawLine(p, 1, 1, Width - 2, 1);
                g.DrawLine(p, Width - 1, 2, Width - 1, Height - 2);
                g.DrawLine(p, 2, Height - 1, Width - 2, Height - 1);
            }
            else if (state == 3)//draw pressed style border
            {
                Pen p = new Pen(SystemColors.ControlDark, 2);
                g.DrawLine(p, 1, 1, 1, Height - 2);
                g.DrawLine(p, 1, 1, Width - 2, 1);
                g.DrawLine(p, Width - 1, 2, Width - 1, Height - 2);
                g.DrawLine(p, 2, Height - 1, Width - 2, Height - 1);
            }
            else if (state == 4)//draw disabled style border
            {
                Pen p = new Pen(SystemColors.ControlLight, 2);
                g.DrawLine(p, 1, 1, 1, Height - 2);
                g.DrawLine(p, 1, 1, Width - 2, 1);
                g.DrawLine(p, Width - 1, 2, Width - 1, Height - 2);
                g.DrawLine(p, 2, Height - 1, Width - 2, Height - 1);
            }
            else if (state == 5)//draw default style border
            {
                Pen p = new Pen(Color.SkyBlue, 2);
                g.DrawLine(p, 1, 1, 1, Height - 2);
                g.DrawLine(p, 1, 1, Width - 2, 1);
                g.DrawLine(p, Width - 1, 2, Width - 1, Height - 2);
                g.DrawLine(p, 2, Height - 1, Width - 2, Height - 1);
            }
            if (state == 4)//draw disable style border
            {
                Pen p = new Pen(Color.FromArgb(161, 161, 146), 1);
                g.DrawLine(p, 0, 2, 0, Height - 3);
                g.DrawLine(p, 2, 0, Width - 3, 0);
                g.DrawLine(p, Width - 1, 2, Width - 1, Height - 3);
                g.DrawLine(p, 2, Height - 1, Width - 3, Height - 1);
                g.DrawLine(p, 0, 2, 2, 0);
                g.DrawLine(p, 0, Height - 3, 2, Height - 1);
                g.DrawLine(p, Width - 3, 0, Width - 1, 2);
                g.DrawLine(p, Width - 3, Height - 1, Width - 1, Height - 3);
            }
            else//draw normal style border
            {
                g.DrawLine(Pens.Black, 0, 2, 0, Height - 3);
                g.DrawLine(Pens.Black, 2, 0, Width - 3, 0);
                g.DrawLine(Pens.Black, Width - 1, 2, Width - 1, Height - 3);
                g.DrawLine(Pens.Black, 2, Height - 1, Width - 3, Height - 1);
                g.DrawLine(Pens.Black, 0, 2, 2, 0);
                g.DrawLine(Pens.Black, 0, Height - 3, 2, Height - 1);
                g.DrawLine(Pens.Black, Width - 3, 0, Width - 1, 2);
                g.DrawLine(Pens.Black, Width - 3, Height - 1,
                    Width - 1, Height - 3);
            }
        }

        private void DrawNormalButton(Graphics g)
        {
            DrawBorder(g, 1);
            PaintBack(g, SystemColors.ControlLightLight);
        }

        private void DrawMouseHoverButton(Graphics g)
        {
            DrawBorder(g, 2);
            PaintBack(g, SystemColors.ControlLightLight);
        }

        private void DrawMouseDownButton(Graphics g)
        {
            DrawBorder(g, 3);
            PaintBack(g, SystemColors.ControlLight);
        }

        private void DrawDisableButton(Graphics g)
        {
            DrawBorder(g, 4);
            PaintBack(g, SystemColors.ControlLight);
        }

        private void DrawContainFocusButton(Graphics g)
        {
            DrawBorder(g, 5);
            PaintBack(g, SystemColors.ControlLightLight);
        }

        private void PaintBack(Graphics g, Color c)
        {
            g.FillRectangle(new SolidBrush(c), 3, 3, Width - 6, Height-6);
        }

        private void WriteText(Graphics g)
        {
            int x = 0, y = 0;
            Size s = g.MeasureString(Text, Font).ToSize();
            x = (Width - s.Width) / 2;
            y = (Height - s.Height) / 2;
            if (Enabled)
                g.DrawString(Text, Font, Brushes.Black, x, y);
            else
                g.DrawString(Text, Font, Brushes.Gray, x, y);
        }
    }
}

窗体代码不变。