实现ASPxGridView基于AJAX和自定义数据源的分页查询

为了实现这个功能，可算是折腾了好久，因为我本人一直在用XpoDataSource绑定，不怎么关注自定义分页数据源的。

首先要明确一点的是，自定义数据源（指绑定到自己写的数据访问层，至于ObjectDataSource可不可以，目前我还没验证过）不支持自动汇总、分组、自动筛选（包括列头筛选）、非绑定列，这在官方文档关于DataSourceForceStandardPaging属性的说明中有提到，如果真要实现这些功能，还要自己写很多非常复杂的代码，个人觉得还不如在GridView外自己实现。也就是说我们可以实现的就是自定义分页及排序。废话少说，贴代码（数据访问层的代码就不贴了）：

前台：

<asp:ScriptManager ID="ScriptManager1" runat="server"> </asp:ScriptManager> <dxwgv:ASPxGridView ID="gv" runat="server" AutoGenerateColumns="False" Width="100%" KeyFieldName="产品ID" ClientInstanceName="gv" > <SettingsPager Mode="ShowAllRecords" Visible="False"> </SettingsPager> <Columns> <dxwgv:GridViewCommandColumn VisibleIndex="0"> </dxwgv:GridViewCommandColumn> <dxwgv:GridViewDataTextColumn FieldName="产品ID" VisibleIndex="1"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataTextColumn FieldName="产品名称" VisibleIndex="2"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataTextColumn FieldName="供应商ID" VisibleIndex="3"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataTextColumn FieldName="类别ID" VisibleIndex="4"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataTextColumn FieldName="单位数量" VisibleIndex="5"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataTextColumn FieldName="单价" VisibleIndex="6"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataTextColumn FieldName="库存量" VisibleIndex="7"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataTextColumn FieldName="订购量" VisibleIndex="8"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataTextColumn FieldName="再订购量" VisibleIndex="9"> </dxwgv:GridViewDataTextColumn> <dxwgv:GridViewDataCheckColumn FieldName="中止" VisibleIndex="10"> </dxwgv:GridViewDataCheckColumn> <dxwgv:GridViewDataTextColumn FieldName="库存" VisibleIndex="11"> </dxwgv:GridViewDataTextColumn> </Columns> </dxwgv:ASPxGridView> <asp:UpdatePanel ID="upPager" runat="server"> <ContentTemplate> <dxpg:ASPxPager ID="Pager" runat="server" SeoFriendly="CrawlerOnly"> <LastPageButton Visible="True"> </LastPageButton> <FirstPageButton Visible="True"> </FirstPageButton> <AllButton Visible="True"> </AllButton> </dxpg:ASPxPager> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="Pager" EventName="PageIndexChanged" /> <asp:AsyncPostBackTrigger ControlID="Pager" EventName="PageIndexChanging" /> </Triggers> </asp:UpdatePanel>

后台：

Imports DevExpress.Xpo.DB Partial Public Class CustomPaging Inherits System.Web.UI.Page Private product As New NorthwindLibrary.BusinessFacade.Product(New DevExpress.Xpo.Session) Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load BindData() End Sub Private Sub BindData() Dim ds As Data.DataSet = product.GetEntityList(GetHeaderFilterExpression(), Pager.PageIndex + 1, Pager.ItemsPerPage, SortFieldName, SortDirection) gv.DataSource = ds gv.DataBind() Pager.ItemCount = ds.Tables(1).Rows(0).Item(1).ToString End Sub Protected Sub gv_BeforeColumnSortingGrouping(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.ASPxGridViewBeforeColumnGroupingSortingEventArgs) Handles gv.BeforeColumnSortingGrouping Select Case e.Column.SortOrder Case DevExpress.Data.ColumnSortOrder.Ascending SortDirection = WebControls.SortDirection.Ascending Case DevExpress.Data.ColumnSortOrder.Descending SortDirection = WebControls.SortDirection.Descending Case Else End Select SortFieldName = e.Column.FieldName BindData() End Sub Protected Sub Pager_PageIndexChanging(ByVal source As Object, ByVal e As DevExpress.Web.ASPxPager.PagerPageEventArgs) Handles Pager.PageIndexChanging Dim js As String = "gv.PerformCallback();" ScriptManager.RegisterStartupScript(Page, Me.GetType(), "", js, True) End Sub ''' <summary> ''' ''' 排序字段 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Public Property SortFieldName() As String Get If Session("SortFieldName") = Nothing Then Session("SortFieldName") = "产品ID" End If Return Session("SortFieldName").ToString End Get Set(ByVal value As String) Session("SortFieldName") = value End Set End Property Public Property SortDirection() As SortDirection Get If Session("SortDirection") = Nothing Then Session("SortDirection") = SortDirection.Ascending End If Return Session("SortDirection") End Get Set(ByVal value As SortDirection) Session("SortDirection") = value End Set End Property Public Function GetHeaderFilterExpression() As String Dim filter As String = String.Empty For Each col In gv.Columns Try If col.FilterExpression <> String.Empty Then filter += col.FilterExpression + " & " End If Catch ex As Exception End Try Next filter = filter.Trim.TrimEnd("&").Replace("&", "AND") If filter <> String.Empty Then filter = "WHERE " & filter End If Return filter End Function Protected Sub gv_CustomColumnSort(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs) Handles gv.CustomColumnSort End Sub Protected Sub gv_CustomDataCallback(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.ASPxGridViewCustomDataCallbackEventArgs) Handles gv.CustomDataCallback End Sub Protected Sub gv_HeaderFilterFillItems(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.ASPxGridViewHeaderFilterEventArgs) Handles gv.HeaderFilterFillItems If e.Column.Settings.AllowHeaderFilter = DevExpress.Web.ASPxClasses.DefaultBoolean.True Then e.Values.Clear() e.AddShowAll() Dim dt As DataTable = product.GetEntityFilterData(e.Column.FieldName, Nothing) For Each row As DataRow In dt.Rows e.AddValue(row(0).ToString, row(0).ToString) Next GetHeaderFilterExpression() End If End Sub End Class

效果图：

本文来源于阿朴的专栏，http://blog.csdn.net/rogerslee/archive/2009/10/03/4631051.aspx