[转]C# winForm 创建水晶风格的按钮

时下水晶风格比较流行，在天极网看到一篇制作水晶按钮控件的文章，

首先启动Visual Studio 2005，新建空白解决方案，我们取名为：TestCrystalButton，

然后在项目导航栏上右击鼠标添加新项目，为此解决方案添加新的C# Windows 控件库，取名为MyControls。

IDE会创建一个继承于UserControl名为UserControl1的类，修改代码使其继承自Button，

并将原文件中所有引用UserControl1名称的地方都更改为CrystalButton，在项目导航栏中把UserControl1.cs更名为CrystalButton.cs

然后将InitializeComponent()方法中的
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
语句注释掉，因为从Button控件不可能有自动缩放功能，它必须依赖于其父控件。

在源文件头部添加对System.Drawing.Imaging和System.Drawing.Drawing2D程序集的引用。

首先需要创建一个枚举类型MouseActionType，当按钮需要绘制时会根据当前鼠标的位置进行不同状态的绘制，

代码如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;

namespace TestCrystalButton
{
public partial class CrystalButton : Button
{
public CrystalButton()
{
InitializeComponent();
}

private enum MouseActionType
{
None,
Hover,
Click
}
private MouseActionType mouseAction;

private GraphicsPath GetGraphicsPath(Rectangle rc, int r)
{
int x = rc.X, y = rc.Y, w = rc.Width, h = rc.Height;
GraphicsPath path = new GraphicsPath();
path.AddArc(x, y, r, r, 180, 90);
//Upper left corner
path.AddArc(x + w - r, y, r, r, 270, 90);
//Upper right cornr
path.AddArc(x + w - r, y + h - r, r, r, 0, 90);
//Lower right corner
path.AddArc(x, y + h - r, r, r, 90, 90);
//Lower left corner
path.CloseFigure();
return path;
}

protected override void OnPaint(PaintEventArgs e)
{
Graphics g = e.Graphics;
g.Clear(SystemColors.ButtonFace);
Color clr = Color.Wheat;//BtnColor;
int shadowOffset = 8;
int btnOffset = 0;
switch(mouseAction)
{
case MouseActionType.Click :
shadowOffset = 4;
clr = Color.LightGray;
btnOffset = 2;
break;
case MouseActionType.Hover:
clr = Color.LightGray;
break;
}
g.SmoothingMode = SmoothingMode.AntiAlias;
// 创建按钮本身的图形
Rectangle rc = new Rectangle(btnOffset, btnOffset, this.ClientSize.Width - 8 - btnOffset, this.ClientSize.Height - 8 - btnOffset);
GraphicsPath path1 = this.GetGraphicsPath(rc, 20);
LinearGradientBrush br1 = new LinearGradientBrush(new Point(0, 0), new Point(0, rc.Height + 6), clr, Color.White);
// 创建按钮阴影
Rectangle rc2 = rc;
rc2.Offset(shadowOffset, shadowOffset);
GraphicsPath path2 = this.GetGraphicsPath(rc2, 20);
PathGradientBrush br2 = new PathGradientBrush(path2);
br2.CenterColor = Color.Black;
br2.SurroundColors = new Color[] { SystemColors.ButtonFace };
//为了更逼真，我们将渐变结束颜色设定为窗体前景颜色，可以根据窗口的前景颜色适当调整
//创建按钮顶部白色渐变
Rectangle rc3 = rc;
rc3.Inflate(-5, -5);
rc3.Height = 15;
GraphicsPath path3 = GetGraphicsPath(rc3, 20);
LinearGradientBrush br3 = new LinearGradientBrush(rc3, Color.FromArgb(255, Color.White), Color.FromArgb(0, Color.White), LinearGradientMode.Vertical);
// 绘制图形
g.FillPath(br2, path2); //绘制阴影
g.FillPath(br1, path1); //绘制按钮
g.FillPath(br3, path3); //绘制顶部白色泡泡
//设定内存位图对象，进行二级缓存绘图操作
Rectangle buttonBitmapRectangle = new Rectangle(rc.Location, rc.Size);
Bitmap buttonBitmap = new Bitmap(buttonBitmapRectangle.Width, buttonBitmapRectangle.Height);
Graphics g_bmp = Graphics.FromImage(buttonBitmap);
g_bmp.SmoothingMode = SmoothingMode.AntiAlias;
g_bmp.FillPath(br1, path1);
g_bmp.FillPath(br3, path3);
//将region赋值给button
Region rgn = new Region(path1);
rgn.Union(path2);
this.Region = rgn;
// 绘制按钮的文本
GraphicsPath path4 = new GraphicsPath();
RectangleF path1bounds = path1.GetBounds();
Rectangle rcText = new Rectangle((int)path1bounds.X + btnOffset, (int)path1bounds.Y + btnOffset, (int)path1bounds.Width, (int)path1bounds.Height);
StringFormat strformat = new StringFormat();
strformat.Alignment = StringAlignment.Center;
strformat.LineAlignment = StringAlignment.Center;
path4.AddString(this.Text, this.Font.FontFamily, (int)this.Font.Style, this.Font.Size, rcText, strformat);
Pen txtPen = new Pen(this.ForeColor, 1);
g.DrawPath(txtPen, path4);
g_bmp.DrawPath(txtPen, path4);
}

}
}

在Windows Application中添加对此dll的引用即可制作出漂亮的水晶控件啦！