为避免无聊灌水之嫌，还是转贴一篇《如何用C#做控件》的文章咯~
其实还是想和大家寒暄一下，哈哈~ ^_^

以创建一个Windows窗体控件为例，介绍C#语言中的继承、属性、重载、文档化、设计器、签名等概念和应用。

步骤：
1．    建立一个空解决方案；
Windows Forms Divider Panel，
2．    然后建立一个Windows控件库项目；
DividerPanel
3．    添加一个类；
DividerPanel.cs
4．    将该类从已有的控件类中继承；
public class DividerPanel : System.Windows.Forms.Panel
{
}
5．    增加属性和访问器；
新增两个属性：
private System.Windows.Forms.Border3DSide borderSide;
private System.Windows.Forms.Border3DStyle border3DStyle;

对于私有变量，使用访问器将其暴露出来：
public System.Windows.Forms.Border3DSide BorderSide
{
    get { return this.borderSide; }
    set
    {
        if( this.borderSide != value )
        {
            this.borderSide = value;
            this.Invalidate();
        }
    }
}

// good
private System.Windows.Forms.Border3DSide borderSide;
// bad
private Border3DSide borderSide;



6．    在构造函数中设置初始值：
public DividerPanel()
{
    // Set default values for our control's properties
    this.borderSide = System.Windows.Forms.Border3DSide.All;
    this.border3DStyle = System.Windows.Forms.Border3DStyle.Etched;
}

7．    法重载继承的方法
protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
    // allow normal control painting to occur first
    base.OnPaint(e);

    // add our custom border
    System.Windows.Forms.ControlPaint.DrawBorder3D (
        e.Graphics,
        this.ClientRectangle,
        this.border3DStyle,
        this.borderSide );
}

8．    增加属性描述和文档化支持
/// <summary>
/// Specifies the sides of the panel to apply a three-dimensional border to.
/// </summary>
[Bindable(true), Category("Border Options"),
DefaultValue(System.Windows.Forms.Border3DSide.All),
Description("Specifies the sides of the panel to apply a
three-dimensional border to.")]
public System.Windows.Forms.Border3DSide BorderSide
{
    get { return this.borderSide; }
    set
    {
        if( this.borderSide != value )
        {
            this.borderSide = value;
            this.Invalidate();
        }
    }
}

9．    增加工具箱支持
增加bitmap图（DividerPanel.bmp）作为显示在工具箱中的图标，存为嵌入资源；
    [ToolboxItem(true)]
[ToolboxBitmap(typeof(DividerPanel))]
public class DividerPanel : System.Windows.Forms.Panel
{
}

10．    增加设计器类
从该控件中去除BorderStyle属性：
添加System.Designer.dll引用；
添加类：DividerPanelDesigner.cs；
将新类从设计器继承：
public class DividerPanelDesigner :
   System.Windows.Forms.Design.ScrollableControlDesigner
{
}
    重载：
protected override void PreFilterProperties(
   System.Collections.IDictionary properties)
{
    properties.Remove("BorderStyle");
}
    增加设计器属性：
[ToolboxItem(true)]
[ToolboxBitmap(typeof(DividerPanel))]
[DesignerAttribute(typeof(DividerPanelDesigner))]
public class DividerPanel : System.Windows.Forms.Panel
{
}

11．    Assembly属性和签名
[assembly: AssemblyTitle("Divider Panel")]
[assembly: AssemblyDescription(
  "A Panel control with selectable border appearance")]
[assembly: AssemblyConfiguration("")]
[assembly: AssemblyCompany("CodeShack")]
[assembly: AssemblyProduct("Divider Panel Tutorial")]
[assembly: AssemblyCopyright("Copyright (c) 2003-2004 CodeShack")]
[assembly: AssemblyTrademark("")]
[assembly: AssemblyCulture("")]

[assembly: AssemblyKeyFile("..\\..\\..\\DividerPanel.snk")]

sn -k [outputfile].snk

12．    使用该控件
添加引用；
拖拽控件到窗体