开发自定义控件 __Textbox控件（1）
  支持postback
   public cass SugaroaInput : WebControl
  {

        private static readonly object EventTextChanged = new object();

        //支持事件
        public event EventHandler TextChanged
        {
            add
            {
                base.Events.AddHandler(EventTextChanged, value);
            }
            remove
            {
                base.Events.RemoveHandler(EventTextChanged, value);
            }
        }

       //post back
        protected virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection)
        {

            //Page.ClientScript.ValidateEvent(postDataKey, string.Empty);  
            string text = this.Text;
            string str2 = postCollection[postDataKey];
            if (!this.ReadOnly && !text.Equals(str2, StringComparison.Ordinal))
            {
                this.Text = str2;
                return true;
            }
            return false;
        }
    
      //输出html  

      protected override void Render(HtmlTextWriter writer)
        {
            if (Page != null)
                Page.VerifyRenderingInServerForm(this);
             writer.Write("<input ");
            writer.WriteAttribute("type", "input");
            writer.WriteAttribute("id", this.ClientID );
            writer.WriteAttribute("name", this.ClientID );
           writer.WriteAttribute("value", this.Text, true);
          writer.Write("/> ");

            base.Render(writer);
        }

   }