我做了个datalist分页出点问题

前台
 <form id="Form1"   runat= "server" action="">   
   共有  <asp:Label   id= "lblRecordCount" runat= "server"   /> 条记录&nbsp;  
    当前为  <asp:Label   id= "lblCurrentPage"   ForeColor="red"   runat= "server"/> /  
    <asp:Label   id= "lblPageCount"   ForeColor= "red"   runat= "server"   /> 页&nbsp;    
      <asp:DataList   id= "score"   runat= "server"   HeaderStyle-BackColor= "#aaaadd"   AlternatingItemStyle-BackColor= "Gainsboro"   EditItemStyle-BackColor= "yellow"   >   
         <ItemTemplate>       <%#   DataBinder.Eval(Container.DataItem, "id ")   %>      
             <div style="z-index: 101; left: 10px; width: 200px; position: relative; top: 10px; float:left;
                 height: 240px">
                 <div style="z-index: 101; left: 0px; width:198px; position: relative; top: 0px;
                 height: 20px">
                  <asp:Label ID="imgmsLabel" runat="server" Text='<%# Eval("imgms") %>'></asp:Label><br />
             </div>
             <div style="z-index: 101; left: 0px; width: 198px; position: relative; top: 0px;
                 height: 198px">
                 <asp:Image ID="Image1" runat="server" ImageUrl='<%# "~/imgsc/"+Eval("imglj") %>'
                     Style="position: relative" /></div>
                 <div style="z-index: 101; left: 0px; width:198px; position: relative; top: 0px;
                 height: 20px">
                     商家名称： <asp:Label ID="imgidLabel" runat="server" Text='<%# Eval("imgid") %>'></asp:Label><br /></div>
             </div>
           </ItemTemplate>   
          <EditItemStyle BackColor="Yellow" />
          <AlternatingItemStyle BackColor="Gainsboro" />
          <EditItemTemplate>
              dsadsa
          </EditItemTemplate>
          <HeaderStyle BackColor="#AAAADD" />
          <SelectedItemTemplate>
              dsadsa
          </SelectedItemTemplate>
        </asp:DataList>   
        <asp:LinkButton   id= "lbnPrevPage"   Text= "上一页"   CommandName= "prev"   OnCommand= "Page_OnClick"   runat= "server"   /> 
        <asp:LinkButton   id= "lbnNextPage"   Text= "下一页"   CommandName= "next"   OnCommand= "Page_OnClick"   runat= "server"   /> 
</form>    
</body>
</html>
后台using System;
using System.Data;
using System.Configuration;
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.Collections;
public partial class Default4: System.Web.UI.Page
{
    ConnDB db = new ConnDB();
    int PageSize, RecordCount, PageCount, CurrentPage;
    public void Page_Load(Object src, EventArgs e)
    {     //设定PageSize   
        PageSize = 4;        //第一次请求执行    
        if (!Page.IsPostBack)
        {
            CurrentPage = 0;
            ViewState["PageIndex "] = 0;
            //计算总共有多少记录      
            RecordCount = CalculateRecord();
            lblRecordCount.Text = RecordCount.ToString();
            //计算总共有多少页     
            if ((RecordCount % PageSize) > 0) PageCount = RecordCount / PageSize + 1;
            else PageCount = RecordCount / PageSize;
            lblPageCount.Text = PageCount.ToString();
            ViewState["PageCount "] = PageCount;
            ListBind();
        }
    }
    //计算总共有多少条记录   
    public int CalculateRecord()
    {
        int intCount;
        string strCount = "select   count(1)   from   img_sp";
        intCount = Int32.Parse(db.ReturnDataSet(strCount).Tables[0].Rows[0][0].ToString());
        return intCount;
    }    ICollection CreateSource()
    {
        int StartIndex;
        //设定导入的起终地址    
        StartIndex = CurrentPage * PageSize;
        string strSel = "select  *   from   img_sp ";
        DataSet ds = new DataSet();
        ds = db.ReturnDataSet(strSel);
        return ds.Tables[0].DefaultView;
    }
    public void ListBind()
    {
        score.DataSource = CreateSource();
        score.DataBind();
        lbnNextPage.Enabled = true;
        lbnPrevPage.Enabled = true;
        if (CurrentPage == (PageCount - 1)) lbnNextPage.Enabled = false;
        if (CurrentPage == 0) lbnPrevPage.Enabled = false;
        lblCurrentPage.Text = (CurrentPage + 1).ToString();
    }
    public void Page_OnClick(Object sender, CommandEventArgs e)
    {
        CurrentPage = (int)ViewState["PageIndex "];
        PageCount = (int)ViewState["PageCount "];
        string cmd = e.CommandName;
        //判断cmd，以判定翻页方向     
        switch (cmd)
        {
            case "next ":
                if (CurrentPage < (PageCount - 1)) CurrentPage++; break;
            case "prev ": if (CurrentPage > 0) CurrentPage--; break;
        }
        ViewState["PageIndex "] = CurrentPage;
        ListBind();
    }
    protected void btnSelect_Click(object sender, EventArgs e)
    {    }
}
这个做出来设置的显示每页4个。结果都显示出来了。显示总页数和当前页正确，求解决