大哥们帮帮忙，无刷新的问题！！！谢谢了！！！

我调用了个RelatedList控件在测试的过程中来出现“未将对象引用设置到对象的实例”

using System;
using System.Data;
using System.Configuration;
using System.Collections;
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.Data.SqlClient;
public partial class lx : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

        if (!Page.IsPostBack)---------这一块的问题出现“未将对象引用设置到对象的实例”，帮忙看看，谢谢！！！！

        {
            ArrayList a = new ArrayList();
            a.Add("DropDownList1");
            a.Add("DropDownList2");
            a.Add("DropDownList3");
            a.Add("DropDownList4");
            RelatedList1.DataSource = @"ArticleCategory.xml";
            RelatedList1.ListID = a;
            RelatedList1.DataBind();
                   }

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        Response.Write(DropDownList1.SelectedItem.Value + "|" + DropDownList1.SelectedItem.Text + "<br>");
        Response.Write(DropDownList2.SelectedItem.Value + "|" + DropDownList2.SelectedItem.Text + "<br>");
        Response.Write(DropDownList3.SelectedItem.Value + "|" + DropDownList3.SelectedItem.Text + "<br>");
        Response.Write(DropDownList4.SelectedItem.Value + "|" + DropDownList4.SelectedItem.Text + "<br>");

    }
}
--------------------编程问答-------------------- RelatedList1.DataSource = @"ArticleCategory.xml";
            RelatedList1.ListID = a;
            RelatedList1.DataBind();
这3行注释掉就好? --------------------编程问答-------------------- 郁闷，不行还是老问题，错误提示使用new 关键字创建对象实列
--------------------编程问答-------------------- RelatedList1.DataSource = @"ArticleCategory.xml";
            RelatedList1.ListID = a;
            RelatedList1.DataBind();

----------------------------
RelatedList1.DataSource = a;
RelatedList1.DataBind(); --------------------编程问答-------------------- 帮顶了 --------------------编程问答-------------------- 请求帮忙！！！！谢谢了 --------------------编程问答-------------------- 没人，帮忙吗？顶上去 --------------------编程问答-------------------- 友情帮顶！ --------------------编程问答-------------------- 路漫漫啊！！！！帮忙 --------------------编程问答-------------------- 有没有人帮帮忙啊 --------------------编程问答-------------------- 有没有人帮忙啊 --------------------编程问答-------------------- 加入ASP。NET C#群吧，群号是：  1873156

补充：.NET技术 ,  ASP.NET