DataGrid的分页处理

#region 数据绑定
protected void SetBind()
{
ds=new DataSet();
WZZY.Func.data_operation dop1= new WZZY.Func.data_operation();
string sql="Select E_ht.bh,htmc,htrq,xm from E_ht,G_yhgl where E_ht.bhyq=G_yhgl.bh";
ds = dop1.ExeSelect(sql);
if(ds!=null)
{
DataGrid1.DataSource = ds.Tables[0].DefaultView;
DataGrid1.DataBind();
this.lblCurrentIndex.Text = Convert.ToString (Convert.ToInt32 (DataGrid1.CurrentPageIndex) +1);
this.lblPageCount .Text =DataGrid1.PageCount.ToString();
droptz();
}
}
#endregion
private void droptz()
{
tz.Items .Clear ();
for(int i=1;i<=DataGrid1.PageCount;i++)
tz.Items.Add (new ListItem (i.ToString (),i.ToString ()));
tz.Items .FindByValue ((DataGrid1.CurrentPageIndex+1) .ToString ()).Selected=true ;
}
// 翻页
public void PagerButtonClick(object sender, EventArgs e)
{
string arg = ((LinkButton)sender).CommandArgument.ToString();
switch(arg)
{
case "next":
if (DataGrid1.CurrentPageIndex < (DataGrid1.PageCount - 1))
{
DataGrid1.CurrentPageIndex += 1;
}
break;
case "prev":
if (DataGrid1.CurrentPageIndex > 0)
{
DataGrid1.CurrentPageIndex -= 1;
}
break;
case "last":
DataGrid1.CurrentPageIndex = (DataGrid1.PageCount - 1);
break;
default:
DataGrid1.CurrentPageIndex = System.Convert.ToInt32(arg);
break;
}
SetBind();
}

以下是网页文本：
-------------------------------------------------------------
<TABLE >
<TBODY>
<TR>
<TD >
<asp:linkbutton id=Linkbutton1 onclick=PagerButtonClick CommandArgument="0" runat="server">首页</asp:linkbutton
<asp:linkbutton id=Linkbutton2 onclick=PagerButtonClick CommandArgument="prev" runat="server">上一页</asp:linkbutton >
<asp:linkbutton id=Linkbutton3 onclick=PagerButtonClick CommandArgument="next" runat="server">下一页</asp:linkbutton>
<asp:linkbutton id=Linkbutton4 onclick=PagerButtonClick CommandArgument="last" runat="server">尾页</asp:linkbutton>
  |   第<asp:label id=lblCurrentIndex runat="server"></asp:label>页/总<asp:label id=lblPageCount runat="server"></asp:label>页   跳转  <asp:dropdownlist id=tz runat="server" AutoPostBack="True"></asp:dropdownlist>
</TD></TR></TBODY></TABLE>