ObjectDataSource+DataPager+GridView+Nhibernate分页

本篇描述如何使用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
    }

reference:Using a DataPager with the GridView Control - Implementing IPageableItemContainer