在后台的static方法中，像sqlDataReader等等一些都不能用了，没效果了解决方法

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.Web.Services;using System.Data.SqlClient;using System.IO;public partial class UserManagement_DepartmentList : System.Web.UI.Page{    public SqlDataReader sdr,sdr1,sdr2;    public static SqlDataReader sdr3;    public Model.Department department;    public Service.DepartmentService ds;     [WebMethod]//这是一个静态方法，因为有些东西不能用，所以我就在这里面调用下面的普通方法    public static string updateDepart()    {        string ids=HttpContext.Current.Request["ids"];        UserManagement_DepartmentList departmentlist = new UserManagement_DepartmentList();        departmentlist.selectByIdToName(ids);//在这里调用下面的方法        return ids;    }    //这是一个非静态的普通方法，测试过没有问题     public void selectByIdToName(string id)    {         if (Util.StringUtils.isNotBlank(id))         {             string[] array = id.Split(",".ToCharArray());             ds = new Service.DepartmentService();             int v;             int.TryParse(array[0], out v);             sdr2 = ds.selectDepartmentById(v);             while (sdr2.Read())//将选择的行id对应的值显示在文本框中             {                 DropDownList3.SelectedValue = sdr2.GetString(2);                 TextBox4.Text = sdr2.GetString(2);                 TextBox5.Text = sdr2.GetString(3);                              }             //Response.Write(DropDownList3.SelectedValue + "|" + TextBox4.Text + "|" + TextBox5.Text);             sdr2.Close();         }                  }}