Coustom web control 自定义控件

简单控件 事件

EventManager
using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;


namespace MyControls
{
    /**//// <summary>
    /// Summary description for MyEventManager.
    /// </summary>
    [DefaultEvent("NextClick"),DefaultProperty("text")]
    public class MyEventManager : System.Web.UI.WebControls.WebControl,IPostBackEventHandler
    {
        
        public event EventHandler NextClick;
        public event EventHandler PreClick;

        [Bindable(true),Category("Behavior"),DefaultValue(""),Description("text ")]
        public string text
        {
            get
            {
                return ( (string)ViewState["text"] == null )? string.Empty:(string)ViewState["text"] ;
            }
            set
            {
                ViewState["text"] = value;
            }
        }

        protected virtual void OnNextClick(EventArgs e)
        {
            if(NextClick != null)
            {
                NextClick(this,EventArgs.Empty);
            }

        }

        protected virtual void OnPreClick(EventArgs e)
        {
            if(PreClick != null)
            {
                PreClick(this,EventArgs.Empty);
            }

        }

        void IPostBackEventHandler.RaisePostBackEvent(string EventArguments)
        {
            if( EventArguments =="Pre" )
            {
                OnPreClick(EventArgs.Empty);
                Page.Trace.Warn("Pre Button Click");
            }
            else
            {
                OnNextClick(EventArgs.Empty);
                Page.Trace.Warn("Next Button Click");
            }
        }

        [Bindable(true), 
            Category("Appearance"), 
            DefaultValue("")] 
        
        
        protected override void Render(HtmlTextWriter output)
        {
            //output.Write(Text);
            this.Attributes.AddAttributes(output);

            output.AddAttribute(HtmlTextWriterAttribute.Onclick,Page.GetPostBackEventReference(this,"Pre"));
            output.AddAttribute("language","javascript");

            output.RenderBeginTag(HtmlTextWriterTag.Button);
            output.Write("Pre");
            output.RenderEndTag();

            output.AddAttribute(HtmlTextWriterAttribute.Onclick,Page.GetPostBackEventReference(this,"Next"));
            output.AddAttribute("language","javascript");

            output.RenderBeginTag(HtmlTextWriterTag.Button);
            output.Write("Next");
            output.RenderEndTag();


            base.Render(output);
        }
    }
}