.NET自定义控件里面将客户端js代码封装在控件里面（在线等待）

Question

刚刚学习自定义控件，一个按钮单击时，希望用javascript弹出alert（‘click’）；并且这句话是在一个js文件里面，我试着写了代码，但是不对，高手，please give me a hand
自定义控件的代码如下：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Web.UI.HtmlControls;namespace WebControlLibrary1
{
    [DefaultProperty("Text")]
    [ToolboxData("<{0}:usejs runat=server></{0}:usejs>")]
    public class usejs : WebControl,ICallbackEventHandler
    {
        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("")]
        [Localizable(true)]
        public string Text
        {
            get
            {
                String s = (String)ViewState["Text"];
                return ((s == null) ? String.Empty : s);
            }            set
            {
                ViewState["Text"] = value;
            }
        }
        public string ClientPath
        {
            get
            {
                string s = (string)ViewState["ClientPath"];
                return ((s == null) ? string.Empty : s);
            }
            set
            {
                ViewState["ClientPath"] = value;
            }
        }
        public string GetCallbackResult()
        {
            return this.Text.ToString();
        }
        public void RaiseCallbackEvent(string eventArgument)
        {        }
        protected override void OnPreRender(EventArgs e)
        {
            base.OnPreRender(e);
            string strJSPath = base.ResolveUrl(Path.Combine(this.ClientPath,@"Js\alertfuntion.js"));
            if (!Page.ClientScript.IsClientScriptBlockRegistered(this.GetType(),"ControlJs"))
            {
                Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "ControlJs", "<script type='text/javascript' src='" + strJSPath + "'></script>",false);
            }
            string strCallbackfunction = "fn";
            string strCallBackReference = Page.ClientScript.GetCallbackEventReference(this, "", strCallbackfunction, "");
            string strCallbackScript = "function executeCallBack(){" + strCallBackReference + ";}";            if (Page.ClientScript.IsClientScriptBlockRegistered(this.GetType(),"executeCallBack")==false)
            {
                Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "executeCallBack", strCallbackScript, true);
            }
        }
        protected override void Render(HtmlTextWriter writer)
        {
            HtmlGenericControl bt = new HtmlGenericControl("Button");
            bt.ID = "btn";
            bt.Attributes["onclick"] = "executeCallBack();";
            bt.RenderControl(writer);
            base.Render(writer);
        }
    }
}
alertfunction.js文件里面的内容很简单
// JScript 文件function fn() {
    alert('click');
}
生成控件没有错，但是就是执行单击的时候，出现不了alert（‘click’）；

Answer 1

我也顶..
 我也才开始学自定义控件. 疑惑中.....