ObjectDataSource+DataPager+GridView+Nhibernate分页

如何使用GridView(需要实现IPageableItemContainer接口)加DataPager实现分页功能。

并使用ObjectDataSource控件来获得数据源实现分页。

1，ObjectDataSource属性设置

SelectMethod：获得分页的数据源。将获得数据源的方法名赋给该属性。

至少传入2个参数，起始页startRowIndex，每页显示页数maximumRows。

SelectCountMethod：获得总数据行数。将获得数据源总行数的方法名赋给该属性。

注意：方法的返回类型必须是int类型（或小于该类型的），不然会

GridView出现容量不足异常（gridview不会抛出此异常，Listview会抛此异常）。

StartRowIndexParameterName：起始页参数，对应方法参数名startRowIndex

MaximumRowsParameterName：每页显示数参数，对应方法参数名maximumRows

EnablePaging：设置为"True"

其它查询参数可以根据情况在SelectParameters中增加相应查询条件参数。

2，DataPager属性设置

PageSize：设置分页的大小，分页时会将该属性的值传递给maximumRows

PagedControlID：分页的控件（GridView，ListView）的ID。

3，GridView属性设置

AllowPaging：设置为"True" 

DataSourceID：ObjectDataSource的ID

4，Nhibernate分页方法：

example:

public IList<ExceptionLog> GetExceptionLogByQuery(DateTime loTime, DateTime hiTime, string appId, int startRowIndex, int maximumRows)
       {
         var result =  this .Session.GetISession().CreateCriteria<ExceptionLog>()
                .Add(Restrictions.Between( "CreateTime" ,loTime,hiTime))
                .Add(Restrictions.Eq( "appId" , appId))
                .SetMaxResults(maximumRows)
                .SetFirstResult(startRowIndex).List<ExceptionLog>();
         return result;
       }

       public int GetExceptionLogByQueryCount(DateTime loTime,DateTime hiTime, string appId)
       {

          var result = this .Session.GetISession().CreateCriteria<ExceptionLog>()
                .Add(Restrictions.Between( "CreateTime" , loTime, hiTime))
               .Add(Restrictions.Eq( "appId" , appId))
               .SetProjection(Projections.RowCount()).UniqueResult< int >();

          return result;

       }

5,例子

<asp:GridView ID= "GridView1" runat= "server" AllowPaging= "True"
       DataSourceID= "ObjectDataSource1" >
   </asp:GridView>
   <asp:DataPager ID= "pager" runat= "server" PageSize= "8"
       PagedControlID= "GridView1" >
       <Fields>
           <asp:NextPreviousPagerField ButtonCssClass= "command" FirstPageText= "«" PreviousPageText= "‹"
               RenderDisabledButtonsAsLabels= "true" ShowFirstPageButton= "true" ShowPreviousPageButton= "true"
               ShowLastPageButton= "false" ShowNextPageButton= "false" />
           <asp:NumericPagerField ButtonCount= "7" NumericButtonCssClass= "command" CurrentPageLabelCssClass= "current"
               NextPreviousButtonCssClass= "command" />
           <asp:NextPreviousPagerField ButtonCssClass= "command" LastPageText= "»" NextPageText= "›"
               RenderDisabledButtonsAsLabels= "true" ShowFirstPageButton= "false" ShowPreviousPageButton= "false"
               ShowLastPageButton= "true" ShowNextPageButton= "true" />
       </Fields>
   </asp:DataPager>
   <asp:ObjectDataSource ID= "ObjectDataSource1" runat= "server" SelectMethod= "GetExceptionLogByQuery"
       SelectCountMethod= "GetExceptionLogByQueryCount" TypeName= "BLL.ExceptionLog"
       StartRowIndexParameterName= "startRowIndex" MaximumRowsParameterName= "maximumRows"
       EnablePaging= "True" >
       <SelectParameters>
           <asp:ControlParameter ControlID= "txtLowTime" Name= "loTime" PropertyName= "Text" Type= "DateTime"
               DefaultValue= "2000-1-1" />
           <asp:ControlParameter ControlID= "txtHiTime" Name= "hiTime" PropertyName= "Text" Type= "DateTime"
               DefaultValue= "2010-11-1" />
           <asp:ControlParameter ControlID= "txtUserId" Name= "userId" PropertyName= "Text" Type= "String"
               DefaultValue= "joe" />
       </SelectParameters>
   </asp:ObjectDataSource>

实现接口：

/// <summary>
   ///
   /// </summary>
   [ToolboxData( "<{0}:GridView runat=server></{0}:GridView>" )]
   public class GridView : System.Web.UI.WebControls.GridView, IPageableItemContainer
   {
       /// <summary>
       /// TotalRowCountAvailable event key
       /// </summary>
       private static readonly object EventTotalRowCountAvailable = new object ();

       /// <summary>
       ///
       /// </summary>
       /// <param name="dataSource"></param>
       /// <param name="dataBinding"></param>
       /// <returns></returns>
       protected override int CreateChildControls(IEnumerable dataSource, bool dataBinding)
       {
           int rows = base .CreateChildControls(dataSource, dataBinding);

           //  if the paging feature is enabled, determine
           //  the total number of rows in the datasource
           if ( this .AllowPaging)
           {
               //  if we are databinding, use the number of rows that were created,
               //  otherwise cast the datasource to an Collection and use that as the count
               int totalRowCount = dataBinding ? rows : ((ICollection)dataSource).Count;

               //  raise the row count available event
               IPageableItemContainer pageableItemContainer = this as IPageableItemContainer;
               this .OnTotalRowCountAvailable(
                   new PageEventArgs(
                       pageableItemContainer.StartRowIndex,
                       pageableItemContainer.MaximumRows,
                       totalRowCount
                   )
               );

               //  make sure the top and bottom pager rows are not visible
               if ( this .TopPagerRow != null )
               {
                   this .TopPagerRow.Visible = false ;
               }

               if ( this .BottomPagerRow != null )
               {
                   this .BottomPagerRow.Visible = false ;
               }
           }

           return rows;
       }

       #region IPageableItemContainer Interface

       /// <summary>
       ///
       /// </summary>
       /// <param name="startRowIndex"></param>
       /// <param name="maximumRows"></param>
       /// <param name="databind"></param>
       void IPageableItemContainer.SetPageProperties(
           int startRowIndex, int maximumRows, bool databind)
       {
           int newPageIndex = (startRowIndex / maximumRows);
           this .PageSize = maximumRows;

           if ( this .PageIndex != newPageIndex)
           {
               bool isCanceled = false ;
               if (databind)
               {
                   //  create the event args and raise the event
                   GridViewPageEventArgs args = new GridViewPageEventArgs(newPageIndex);
                   this .OnPageIndexChanging(args);

                   isCanceled = args.Cancel;
                   newPageIndex = args.NewPageIndex;
               }

               //  if the event wasn't cancelled
               //  go ahead and change the paging values
               if (!isCanceled)
               {
                   this .PageIndex = newPageIndex;

                   if (databind)
                   {
                       this .OnPageIndexChanged(EventArgs.Empty);
                   }
               }

               if (databind)
               {
                   this .RequiresDataBinding = true ;
               }
           }
       }

       /// <summary>
       ///
       /// </summary>
       int IPageableItemContainer.StartRowIndex
       {
           get { return this .PageSize * this .PageIndex; }
       }

       /// <summary>
       ///
       /// </summary>
       int IPageableItemContainer.MaximumRows
       {
           get { return this .PageSize; }
       }

       /// <summary>
       ///
       /// </summary>
       event EventHandler<PageEventArgs> IPageableItemContainer.TotalRowCountAvailable
       {
           add { base .Events.AddHandler(GridView.EventTotalRowCountAvailable, value); }
           remove { base .Events.RemoveHandler(GridView.EventTotalRowCountAvailable, value); }
       }

       /// <summary>
       ///
       /// </summary>
       /// <param name="e"></param>
       protected virtual void OnTotalRowCountAvailable(PageEventArgs e)
       {
           EventHandler<PageEventArgs> handler = (EventHandler<PageEventArgs>) base .Events[GridView.EventTotalRowCountAvailable];
           if (handler != null )
           {
               handler( this , e);
           }
       }

       #endregion
   }