AspNetPager查询分页问题（点击页码，不再是查询后的数据集）viewstate解决

  public string SQL = "select * from Memorandum";
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                ViewState["SQL"] = SQL;
                BindData();
            }
            if (Request.QueryString["MId"] != null)
            {
                Delete(int.Parse(Request.QueryString["MId"].ToString()));
            }
        }

        protected void AspNetPager1_PageChanged(object sender, EventArgs e)
        {
            BindData();
        }
       
        void BindData()
        {
            PagedDataSource pds = new PagedDataSource();
            IList<MemorandumInfo> Infos = new DAL.Memorandum().GetAllMemorandumsBySQL(ViewState["SQL"].ToString());

            pds.DataSource = Infos;
            pds.AllowPaging = true;
            pds.PageSize = 10;//取控件的分页大小
            pds.CurrentPageIndex = this.AspNetPager1.CurrentPageIndex - 1;//显示当前页
            //设置控件
            this.AspNetPager1.RecordCount = Infos.Count;//记录总数
            this.AspNetPager1.PageSize = 10;
            Repeater1.DataSource = pds;
            Repeater1.DataBind();
        }
        void Delete(int MId)
        {
            new Memorandum().DeleteMemorandum(MId);
            Response.Write("<script>alert('成功删除该条备忘信息');location='?';</script>");
        }
        /// <summary>
        /// 查询
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>

        protected void Button1_Click(object sender, EventArgs e)
        {
            if (DropDownList1.SelectedValue == "0")
            {
                ViewState["SQL"] = "select * from Memorandum";
                BindData();
            }
            else
            {
                ViewState["SQL"] = "SELECT   MId, MemoTitle, MemoContent, MemoStartTime, MemoEndTime FROM  Memorandum WHERE (MemoEndTime - NOW() <=7)";
                BindData();
            }
        }
    }

ViewState 用来跟踪和保存控件的状态信息。否则这些信息可能会丢失，原因可能是这些值不随着 form 回发，或者根本就不在 page 的 html 中。
ViewState 中保存着代码中改变的控件属性，通过代码绑定到控件的任何数据，以及由用户操作触发，回发的任何更改。
ViewState 还提供了一个状态包(StateBag), 这是一个特殊的集合或字典(collection or dictionary), 可以用来保存，通过一个 key 来恢复任意的对象或者值。

赋值：ViewState[key] = value;

取值：value = ViewState[key];