服务器控件开发 绑定事件

using System;using System.Collections.Generic;using System.ComponentModel;using System.Linq;using System.Text;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.Collections.Specialized;namespace ServerControl{    [DefaultProperty("Text")]    [DefaultEvent("TextChanged")]    [ToolboxData("<{0}:KingTextBoxCanPostevent runat=server></{0}:KingTextBoxCanPostevent>")]    public class KingTextBoxCanPostevent : Control,IPostBackDataHandler,IRaiseItemChangedEvents    {        public KingTextBoxCanPostevent() { }        public string Text        {            get             {                String s = (String)ViewState["Text"];                return ((s == null) ? String.Empty : s);            }            set            {                 ViewState["Text"]=value;            }        }        public bool AutoBostBack        {            get;            set;        }        protected override void OnPreRender(EventArgs e)        {            PostBackOptions pbo = new PostBackOptions(this);            pbo.AutoPostBack = AutoBostBack;            pbo.PerformValidation = true;            pbo.TrackFocus = true;            pbo.ClientSubmit = true;            pbo.RequiresJavaScriptProtocol = false;            string strPostBackCode = this.Page.ClientScript.GetPostBackEventReference(pbo);            StringBuilder strPostBackFromClient = new StringBuilder();            strPostBackFromClient.Append(" function PostBackFromClient_"+this.ClientID+"()");            strPostBackFromClient.Append("{");            strPostBackFromClient.Append(strPostBackCode+";");            strPostBackFromClient.Append("}");            if (!Page.ClientScript.IsClientScriptBlockRegistered(this.GetType(), "PostBackFromClient_" + this.ClientID))            {                Page.ClientScript.RegisterClientScriptBlock(this.GetType(),"PostBackFromClient_"+this.ClientID,strPostBackFromClient.ToString(),true);            }            base.OnPreRender(e);        }        protected override void Render(HtmlTextWriter writer)        {            //base.Render(writer);            StringBuilder sb = new StringBuilder();            sb.Append("<input type=\"text\" name=");            sb.Append("\""+this.UniqueID+"\"");            sb.Append(" value=");            sb.Append("\"" + HttpUtility.HtmlEncode(Text)+ "\"");            sb.Append(" onblur='" + "PostBackFromClient_" + this.ClientID + "();'");            sb.Append(" />");            writer.Write(sb.ToString());        }        public virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection)        {            string strOldValue = Text;            string strNewValue = postCollection[this.UniqueID];            if (strOldValue == null || (strOldValue != null && !strOldValue.Equals(strNewValue)))            {                this.Text = strNewValue;                return true;            }            return false;        }        public event EventHandler TextChanged;        protected virtual void OnTextChanged(EventArgs e)        {            if (TextChanged != null)            {                TextChanged(this, e);            }        }        #region IRaiseItemChangedEvents Members        public bool RaisesItemChangedEvents        {            get { throw new NotImplementedException(); }        }        #endregion        #region IPostBackDataHandler Members        public void RaisePostDataChangedEvent()        {            OnTextChanged(EventArgs.Empty);        }        #endregion    }}-------------------------------------------------------------------------------------

复合控件的事件处理机制：

private static readonly object TextChangedKeyObject = new object();        public event EventHandler TextChanged2        {            add            {                base.Events.AddHandler(TextChangedKeyObject, value);            }            remove            {                base.Events.RemoveHandler(TextChangedKeyObject, value);            }        }        protected virtual void OnTextChanged2(EventArgs e)        {            EventHandler handler = base.Events[TextChangedKeyObject] as EventHandler;            if (handler != null)            {                handler(this, e);            }        }