2.0下复合控件的简单开发

看了一下Net2.0的Sdk,于是就写下了这篇文章，2.0下复合控件的简单开发。文章是给初学者看的。。高手就跳过吧。

2.0下面多了个抽象类 CompositeControl，这个类是继承了WebControl的，并实现了INamingContainer,ICompositeControlDesignerAccessor接口。这个跟1.X有点不一样，当然，我们也可以继承WebControl来写复合控件。
其中:INamingContainer的作用是保证子控件的ID是唯一的。
ICompositeControlDesignerAccessor一看就知道是设计是用的。
2.0里面的一些复合控件，如Login,Wizard都是基础这个CompositeControl开发的。
CompositeControl重写了WebControl的Controls属性，DataBind方法。其中DataBind还有重载方法。
下面简单的写出一个注册复合控件，复合控件是包括TextBox,Button,RequiredFieldValidator，Label等。实现的功能有，用户提交时，客户端判断是否已录入用户名，邮箱。。提交后触发一个自定义的事件。小弟才疏学浅，如有问题，欢迎赐教。。。点击这里下载源码

代码如下：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Security.Permissions;
using System.ComponentModel;
namespace WebControls
{

   /**//// <summary>
   /// 获取控件事件的参数类。。
   /// </summary>
   public class SubmitEventArgs
   {
       public SubmitEventArgs(string email, string name)
       {
           this.email = email;
           this.name = name;
       }
       public SubmitEventArgs() { }
       private string email,name;
       public string Email
       {
           get{
               return email;
           }
           set { email = value; }
       }

       public string Name
       {
           get{
               return name;
           }
           set{
               name=value;
           }
       
       }
   }     

    /**//// <summary>
    /// 复合控件Register
    /// </summary>
    [ToolboxData("<{0}:Register runat=server></{0}:Register>")]
    [DefaultEvent("Submit")]
    [DefaultProperty("ButtonText")]
    public class Register : CompositeControl
    {
        public Register() { }

        public Button submitButton, resetButton;
        private TextBox nameTextBox, emailTextBox;
        private Label nameLabel, emailLabel;
        private RequiredFieldValidator emailValidator, nameValidator;
        private static readonly object EventSubmitKey = new object();

     
         public delegate void SubmiteEventHandler(object sender, SubmitEventArgs e);

        "Property"#region"Property"
        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("登入")]
        [Description("登入按钮的标签文字")]
        public string SubmitButtonText
        {
            get
            {
                EnsureChildControls();
                return submitButton.Text;
            }
            set
            {
                EnsureChildControls();
                submitButton.Text = value;
            }
        }


        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("")]
        [Description("注册帐户")]
        public string Name
        {
            get
            {
                EnsureChildControls();
                return nameTextBox.Text;
            }
            set
            {
                EnsureChildControls();
                nameTextBox.Text = value;
            }
        }
        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("")]
        [Description("帐户错误信息")]
        public string NameErrorMessage
        {
            get
            {
                EnsureChildControls();
                return nameValidator.ErrorMessage;
            }
            set
            {
                EnsureChildControls();
                nameValidator.ErrorMessage = value;
                nameValidator.ToolTip = value;
            }
        }

        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("帐户")]
        [Description("帐户标签")]
        public string NameLabelText
        {
            get
            {
                EnsureChildControls();
                return nameLabel.Text;
            }
            set
            {
                EnsureChildControls();
                nameLabel.Text = value;
            }
        }

        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("")]
        [Description("邮件")]
        public string Email
        {
            get
            {
                EnsureChildControls();
                return emailTextBox.Text;
            }
            set
            {
                EnsureChildControls();
                emailTextBox.Text = value;
            }
        }


        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("")]
        [Description("邮件错误信息")]
        public string EmailErrorMessage
        {
            get
            {
                EnsureChildControls();
                return emailValidator.ErrorMessage;
            }
            set
            {
                EnsureChildControls();
                emailValidator.ErrorMessage = value;
                emailValidator.ToolTip = value;
            }
        }

        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("邮件")]
        [Description("邮件标签名称")]
        public string EmailLabelText
        {
            get
            {
                EnsureChildControls();
                return emailLabel.Text;
            }
            set
            {
                EnsureChildControls();
                emailLabel.Text = value;
            }
        }




        #endregion

        "Event"#region"Event"
        [Category("Action")]
        [Description("Raised When the user clicks the button")]
        public event SubmiteEventHandler Submit
        {
            add
            {
                Events.AddHandler(EventSubmitKey, value);
            }
            remove
            {
                Events.RemoveHandler(EventSubmitKey, value);
            }
        }

        protected void OnSubmit(EventArgs e)
        {
            SubmiteEventHandler submitHandler = (SubmiteEventHandler)Events[EventSubmitKey];
            if (submitHandler != null)
            {
                submitHandler(this, new SubmitEventArgs(this.Email, this.Name));
            }

        }

        #endregion


        /**//// <summary>
        /// 2.0新增的方法。。
        /// </summary>
        protected override void RecreateChildControls()
        {
            base.RecreateChildControls();
            EnsureChildControls();
        }

        protected override void CreateChildControls()
        {
            Controls.Clear();
            nameLabel = new Label();
            nameTextBox = new TextBox();
            nameTextBox.ID = "nameTextbox";

            nameValidator = new RequiredFieldValidator();
            nameValidator.ID = "validator1";
            nameValidator.ControlToValidate = nameTextBox.ID;
            nameValidator.Text = "帐户不能为空";
            nameValidator.Display = ValidatorDisplay.Static;


            emailLabel = new Label();
            emailTextBox = new TextBox();
            emailTextBox.ID = "emailTextBox";

            emailValidator = new RequiredFieldValidator();
            emailValidator.ID = "validator2";
           
            emailValidator.ErrorMessage = "邮件不能为空";
           
            emailValidator.ControlToValidate = emailTextBox.ID;
            emailValidator.Display = ValidatorDisplay.Static;


            submitButton = new Button();
            submitButton.ID = "button1";
            submitButton.Text = "登入";
            submitButton.ValidationGroup = this.ID;
            nameValidator.ValidationGroup = this.ID;
            emailValidator.ValidationGroup = this.ID;
            submitButton.Click += new EventHandler(submitButton_Click);



            Controls.Add(nameLabel);
            Controls.Add(nameTextBox);
            Controls.Add(nameValidator);
            Controls.Add(emailLabel);
            Controls.Add(emailTextBox);
            Controls.Add(emailValidator);
            Controls.Add(submitButton);


        }

        void submitButton_Click(object sender, EventArgs e)
        {
            OnSubmit(e);
        }


        protected override void RenderContents(HtmlTextWriter writer)
        {
          //  base.RenderContents(writer);
            AddAttributesToRender(writer);
            writer.AddAttribute(HtmlTextWriterAttribute.Width, "100%");
            writer.AddAttribute(HtmlTextWriterAttribute.Border, "1");
            writer.AddAttribute(HtmlTextWriterAttribute.Cellpadding, "1", false);
            writer.RenderBeginTag(HtmlTextWriterTag.Table);


            writer.RenderBeginTag(HtmlTextWriterTag.Tr);
            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            nameLabel.RenderControl(writer);
            writer.RenderEndTag();

            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            nameTextBox.RenderControl(writer);
            writer.RenderEndTag();

            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            nameValidator.RenderControl(writer);
            writer.Write("&nbsp");
            writer.RenderEndTag();

            writer.RenderEndTag();



            writer.RenderBeginTag(HtmlTextWriterTag.Tr);
            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            emailLabel.RenderControl(writer);
            writer.RenderEndTag();


            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            emailTextBox.RenderControl(writer);
            writer.RenderEndTag();

            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            emailValidator.RenderControl(writer);
            writer.Write("&nbsp");
            writer.RenderEndTag();

            writer.RenderEndTag();


            writer.RenderBeginTag(HtmlTextWriterTag.Tr);
            writer.AddAttribute(HtmlTextWriterAttribute.Colspan, "2", false);
            writer.AddAttribute(HtmlTextWriterAttribute.Align, "right", false);
            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            submitButton.RenderControl(writer);
            writer.RenderEndTag();
            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            writer.Write("&nbsp");
            writer.RenderEndTag();
            writer.RenderEndTag();

            writer.RenderEndTag();

        }



    }
}

我是直接放入App_Code文件夹里面的。这样做的好处是不用编译都可以调用。
测试页default.aspx,代码如下：

<%@ Page Language="C#"  EnableViewState="false" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>
<%@ Register  TagPrefix="index"  Namespace="WebControls"  %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">        
        <index:Register runat=server EmailLabelText="邮件" ID=reg NameLabelText="名称"  SubmitButtonText="登入"  Email="Genson_diy@sina.com" OnSubmit="reg_Submit" />
    </form>
</body>
</html>

cs 代码如下：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using WebControls;
public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
       
    }

    protected void reg_Submit(object sender, SubmitEventArgs e)
    {
        Response.Write(e.Name + e.Email);
        
    }
}