DataGrid同时具有分页和排序功能及注意点

    当datagrid同时具有分页和排序功能时应注意在重新绑定数据源时，mydatagrid.currentpageindex=0;
下面给实现以上功能的原码，也就不多缀了aspx中包含有datagrid和控制其数据源变化的dropdownlist
datagrid代码
  <asp:datagrid id="mydatagrid" runat="server" bordercolor="#cccccc" font-size="100%" horizontalalign="center"
            autogeneratecolumns="false" ondeletecommand="mydatagrid_delete" onsortcommand="sort_grid" onpageindexchanged="mydatagrid_pageindexchanged"
            datakeyfield="acc_no" pagerstyle-position="bottom" pagerstyle-horizontalalign="center" pagerstyle-mode="nextprev"
            pagesize="10" allowsorting="true" allowpaging="true" cellpadding="4" width="100%">
            <alternatingitemstyle backcolor="#e9e9e6"></alternatingitemstyle>
            <headerstyle font-bold="true" wrap="false" forecolor="white" backcolor="#999999"></headerstyle>
            <columns>
             <asp:buttoncolumn text="口" commandname="delete"></asp:buttoncolumn>
             <asp:boundcolumn datafield="no" sortexpression="no" readonly="true" headertext="序号"></asp:boundcolumn>
             <asp:boundcolumn datafield="id" sortexpression="id" headertext="id"></asp:boundcolumn>
             <asp:boundcolumn datafield="name" sortexpression="name" headertext="名称"></asp:boundcolumn>
             <asp:boundcolumn datafield="c_name" sortexpression="c_name" headertext="各科名称"></asp:boundcolumn>
             <asp:boundcolumn datafield="flg" sortexpression="flg" headertext="项目"></asp:boundcolumn>
            </columns>
            <pagerstyle nextpagetext="下10件" prevpagetext="返回" horizontalalign="center"></pagerstyle>
           </asp:datagrid>

dropdownlist代码
<asp:dropdownlist id="ddlwk" runat="server" autopostback="true" enabled="false">
               <asp:listitem value="0">东京</asp:listitem>
               <asp:listitem value="3">九州</asp:listitem>
               <asp:listitem value="8">北海道</asp:listitem>
               <asp:listitem value="9">四国</asp:listitem>
              </asp:dropdownlist>

 

aspx.cs文件代码核心如下：
private void page_load(object sender, system.eventargs e)
  {
   if(!ispostback)
   {
       session["wp"] ="0";
       ddlwk_gets();
       bindgrid();
   } 
  }
  private void ddlwk_gets()
  {
   switch (session["wp"].tostring())
   {
    case "0":ddlwk.selectedindex=0;
     break;
    case "3":ddlwk.selectedindex=1;
     break;
    case "8":ddlwk.selectedindex=2;
     break;
    case "9":ddlwk.selectedindex=3;
     break;
    default:ddlwk.selectedindex=0;
     break;
   }
  }
  protected void bindgrid()
  {
   mydatagrid.datasource=getdata().tables["vco"].defaultview;
   mydatagrid.databind();
   //count.text=mydatagrid.columns.count.tostring();
  }

  /// <summary>
  /// 返回data
  /// </summary>
  ///<returns></returns>
  private dataset getdata()
  {
   string strconn=(string) ((namevaluecollection) context.getconfig("system.web/database"))["strconn"];
   using (sqlconnection conn = new sqlconnection(strconn))
   {
    sqlcommand cmd = new sqlcommand("sp_c",conn);
    cmd.commandtype=commandtype.storedprocedure;
    cmd.parameters.add("@place",sqldbtype.varchar,2);
    cmd.parameters["@place"].value=session["wp"].tostring();
    conn.open();

    sqldataadapter da = new sqldataadapter();
    da.selectcommand=cmd;
    dataset ds=new dataset();
    da.fill(ds,"vco");
    count.text="ヒット："+ds.tables["vco"].rows.count.tostring()+"件";
    return ds;
   }

  }
  /// <summary>
  ///从dataset中除一
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  protected void mydatagrid_delete(object sender, datagridcommandeventargs e)
  {
    string strid=mydatagrid.datakeys[(int)e.item.itemindex].tostring();
    //删除操作
  }
  /// <summary>
  /// 分页操作
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  protected void mydatagrid_pageindexchanged(object source, datagridpagechangedeventargs e)
  {
   mydatagrid.currentpageindex=e.newpageindex;
   bindgrid();
  }
  /// <summary>
  /// 排序
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  protected void sort_grid(object sender, datagridsortcommandeventargs e)
  {
   dataview dv= new dataview(getdata().tables["vco"]);
   dv.sort= e.sortexpression.tostring();
   mydatagrid.datasource=dv;
   mydatagrid.databind();
  }

  #region web   override protected void oninit(eventargs e)
  {
   //   //
   initializecomponent();
   base.oninit(e);
  }

  /// <summary>  /// </summary>
  private void initializecomponent()
  {   
   this.ddlwk.selectedindexchanged += new system.eventhandler(this.ddlwk_selectedindexchanged);
   this.load += new system.eventhandler(this.page_load);

  }
  #endregion

  private void ddlwk_selectedindexchanged(object sender, system.eventargs e)
  {
   session["wp"]=ddlwk.selectedvalue;
   mydatagrid.currentpageindex=0;//没有这一句，当该页码超出其他数据源的范围时会出错
   bindgrid();
   response.write( "<script language='javascript'>parent.menuframe.location.reload();</script>");

  }