嗨，任何人都可以帮我解决这个问题。我正在使用动态数据并创建了一个自定义页面，该页面显示数据库表中的所有订单。一旦有人选择了一个订单，我希望它显示该订单的所有单个项目。此数据存储在另一个表中，但在同一个数据库中。我在这里发现了一篇非常有用的文章Asp.net Dynamic data multiple relational entity on single page，我认为这几乎给了我我的答案，但我被困在关于实现 IEnumerable 的部分（我正在尝试在这页纸）。我在 IEnumerable 上做了一些阅读，但我真的迷路了。我不确定我是否应该创建一个新课程。任何人都可以帮忙吗？
这是我到目前为止的代码：
HTML 代码：
<h2 class="DDSubHeader">Catering Request Orders</h2>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<div class="DD">
<asp:ValidationSummary ID="ValidationSummary1" runat="server" EnableClientScript="true"
HeaderText="List of validation errors" CssClass="DDValidator" />
<asp:DynamicValidator runat="server" ID="GridViewValidator" ControlToValidate="GridView1" Display="None" CssClass="DDValidator" />
<asp:DynamicValidator runat="server" ID="FormViewValidator" ControlToValidate="FormView1" Display="None" CssClass="DDValidator" />
<asp:QueryableFilterRepeater runat="server" ID="FilterRepeater">
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Eval("DisplayName") %>' OnPreRender="Label_PreRender" />
<asp:DynamicFilter runat="server" ID="DynamicFilter" OnFilterChanged="DynamicFilter_FilterChanged" /><br />
</ItemTemplate>
</asp:QueryableFilterRepeater>
<br />
<asp:Button ID="searchButton" runat="server" Text="Search" OnClick="SearchButton_Click" />
</div>
<asp:GridView ID="GridView1" runat="server" DataSourceID="GridDataSource" EnablePersistedSelection="True"
AutoGenerateSelectButton="True"
AutoGenerateColumns="False"
AllowPaging="True" AllowSorting="True" OnDataBound="GridView1_DataBound"
OnRowEditing="GridView1_RowEditing" OnSelectedIndexChanging="GridView1_SelectedIndexChanging"
OnRowDeleted="GridView1_RowDeleted" OnRowUpdated="GridView1_RowUpdated"
OnRowCreated="GridView1_RowCreated" CssClass="DDGridView"
RowStyle-CssClass="td" HeaderStyle-CssClass="th" CellPadding="6">
<Columns>
<%--<asp:TemplateField>
<ItemTemplate>
<asp:DynamicHyperLink ID="DynamicHyperLink1" runat="server" Text="Details" />
<a id="CategoryRouteID" runat="server" href= '<%# GetRouteInformation() %>'/>
<%-- <asp:DynamicHyperLink ID="DynamicHyperLink1" runat="server" Text="Details" />
<!-- Create action link to filter items that
belong to the same category -->
<a ID="CategoryRouteID" runat="server" href='<%# GetRouteInformation() %>'>
</a></asp:DynamicHyperLink>
</ItemTemplate>
</asp:TemplateField>--%>
<asp:DynamicField DataField="OrderNo" HeaderText="Order No" />
<asp:DynamicField DataField="DisplayName" HeaderText="Display name" />
<asp:DynamicField DataField="EmailAddress" HeaderText="Email address" />
<asp:DynamicField DataField="DeliveryDate" HeaderText="Delivery date" />
<asp:DynamicField DataField="Time" HeaderText="Time" />
<asp:DynamicField DataField="Location" HeaderText="Location" />
<asp:DynamicField DataField="Site" HeaderText="Site" />
<asp:DynamicField DataField="OrderProgress" HeaderText="Order progress" />
<asp:DynamicField DataField="tblCateringOrdersDetailsItems" HeaderText="Item details" />
</Columns>
<HeaderStyle CssClass="th" />
<PagerStyle CssClass="DDFooter" />
<RowStyle CssClass="td" />
<SelectedRowStyle CssClass="DDSelected" />
<PagerTemplate>
<asp:GridViewPager ID="GridViewPager1" runat="server" />
</PagerTemplate>
<EmptyDataTemplate>
There are currently no items in this table.
</EmptyDataTemplate>
<SortedAscendingHeaderStyle BackColor="#DEDFF0" Font-Bold="True" />
<SortedDescendingHeaderStyle BackColor="#DEDFF0" Font-Bold="True" />
</asp:GridView>
<asp:EntityDataSource ID="GridDataSource" runat="server" EnableDelete="true" EnableUpdate="true" />
<asp:QueryExtender ID="GridQueryExtender" TargetControlID="GridDataSource" runat="server">
<asp:DynamicFilterExpression ControlID="FilterRepeater" />
</asp:QueryExtender>
<asp:Panel ID="DetailsPanel" runat="server">
<br /><br />
<asp:FormView ID="FormView1" runat="server" DataSourceID="DetailsDataSource" RenderOuterTable="false"
OnPreRender="FormView1_PreRender" OnModeChanging="FormView1_ModeChanging" OnItemUpdated="FormView1_ItemUpdated"
OnItemInserted="FormView1_ItemInserted" OnItemDeleted="FormView1_ItemDeleted" OnItemCommand="FormView1_ItemCommand">
<HeaderTemplate>
<table id="detailsTable" class="DDDetailsTable" cellpadding="6">
</HeaderTemplate>
<ItemTemplate>
<tr class="td">
<td class="DDLightHeader">Order No</td>
<td><asp:DynamicControl ID="OrderNo" runat="server" DataField="OrderNo" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">User ID</td>
<td><asp:DynamicControl runat="server" DataField="UserID" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Display Name</td>
<td><asp:DynamicControl runat="server" DataField="DisplayName" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Email Address</td>
<td><asp:DynamicControl ID="EmailAddress" runat="server" DataField="EmailAddress" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Project Code</td>
<td><asp:DynamicControl runat="server" DataField="ProjectCode" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Event Description</td>
<td><asp:DynamicControl runat="server" DataField="EventDesc" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Delivery Date</td>
<td><asp:DynamicControl runat="server" DataField="DeliveryDate" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Date Ordered</td>
<td><asp:DynamicControl runat="server" DataField="DateOrdered" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Site</td>
<td><asp:DynamicControl runat="server" DataField="Site" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Time</td>
<td><asp:DynamicControl runat="server" DataField="Time" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Location</td>
<td><asp:DynamicControl runat="server" DataField="Location" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Additional Information</td>
<td><asp:DynamicControl runat="server" ID="AdditionalInfo" DataField="AdditionalInfo" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Item Costs</td>
<td><asp:DynamicControl runat="server" ID="ItemCosts" DataField="ItemCosts" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">AdditionalCosts</td>
<td><asp:DynamicControl runat="server" ID="AdditionalCosts" DataField="AdditionalCosts" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Total Costs</td>
<td><asp:DynamicControl runat="server" DataField="TotalCosts" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">More Information Required</td>
<td><asp:DynamicControl runat="server" DataField="MoreInformationRequired" UIHint="MultilineText" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Reason Rejected</td>
<td><asp:DynamicControl runat="server" DataField="ReasonRejected" UIHint="MultilineText" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Order Progress</td>
<td><asp:DynamicControl runat="server" DataField="OrderProgress" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Imported Into Dream</td>
<td><asp:DynamicControl runat="server" DataField="ImportedIntoDream" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">View Items</td>
<td><asp:DynamicControl runat="server" DataField="tblCateringOrdersDetailsItems" /></td>
</tr>
<%--<asp:DynamicEntity ID="DynamicEntity1" runat="server" />--%>
<tr class="td">
<td colspan="2">
<asp:LinkButton ID="LinkButton1" runat="server" CommandName="Edit" Text="Edit" />
<asp:LinkButton ID="LinkButton2" runat="server" CommandName="Delete" Text="Delete"
OnClientClick='return confirm("Are you sure you want to delete this item?");' />
<%-- <asp:LinkButton ID="LinkButton3" runat="server" CommandName="New" Text="New" />--%>
</td>
</tr>
</ItemTemplate>
<EditItemTemplate>
<tr class="td">
<td class="DDLightHeader">Order No</td>
<td><asp:DynamicControl ID="OrderNo" runat="server" DataField="OrderNo" Mode="ReadOnly"/></td>
</tr>
<tr class="td">
<td class="DDLightHeader">User ID</td>
<td><asp:DynamicControl runat="server" DataField="UserID" Mode="ReadOnly"/></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Display Name</td>
<td><asp:DynamicControl runat="server" DataField="DisplayName" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Email Address</td>
<td><asp:DynamicControl runat="server" DataField="EmailAddress" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Project Code</td>
<td><asp:DynamicControl runat="server" DataField="ProjectCode" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Event Description</td>
<td><asp:DynamicControl runat="server" DataField="EventDesc" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Delivery Date</td>
<td><asp:DynamicControl runat="server" DataField="DeliveryDate" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Date Ordered</td>
<td><asp:DynamicControl runat="server" DataField="DateOrdered" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Site</td>
<td><asp:DynamicControl runat="server" DataField="Site" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Time</td>
<td><asp:DynamicControl runat="server" DataField="Time" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Location</td>
<td><asp:DynamicControl runat="server" DataField="Location" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Additional Information</td>
<td><asp:DynamicControl runat="server" DataField="AdditionalInfo" Mode="ReadOnly" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Item Costs</td>
<td><asp:DynamicControl runat="server" ID="ItemCosts" DataField="ItemCosts" Mode="Edit" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Additional Costs</td>
<td><asp:DynamicControl runat="server" ID="AdditionalCosts" DataField="AdditionalCosts" Mode="Edit" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Total Costs</td>
<td><asp:DynamicControl runat="server" ID="TotalCosts" DataField="TotalCosts" Mode="Edit" /></td>
<%--<td><asp:Button runat="server" ID="btnCalculateTotalCosts" Text="Calculate total costs" CommandName="Calculate" /></td>--%>
<%-- <asp:Button ID="btnUpdateOrder" runat="server" onclick="btnUpdateOrder_Click"
Text="Update Order" />--%>
</tr>
<tr class="td">
<td class="DDLightHeader">More Information Required</td>
<td><asp:DynamicControl runat="server" DataField="MoreInformationRequired" Mode="Edit" UIHint="MultilineText" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Reason Rejected</td>
<td><asp:DynamicControl runat="server" DataField="ReasonRejected" Mode="Edit" UIHint="MultilineText" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Order Progress</td>
<td><asp:DynamicControl runat="server" DataField="OrderProgress" Mode="Edit" UIHint="OrderProgressDropDown" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">Imported Into Dream</td>
<td><asp:DynamicControl runat="server" DataField="ImportedIntoDream" Mode="Edit" /></td>
</tr>
<tr class="td">
<td class="DDLightHeader">View Items</td>
<td><asp:DynamicControl runat="server" DataField="tblCateringOrdersDetailsItems" Mode="Edit" /></td>
</tr>
<%--<asp:DynamicEntity ID="DynamicEntity2" runat="server" Mode="Edit" />--%>
<tr class="td">
<td colspan="2">
<asp:LinkButton ID="LinkButton4" runat="server" CommandName="Update" Text="Update" />
<asp:LinkButton ID="LinkButton5" runat="server" CommandName="Cancel" Text="Cancel" CausesValidation="false" />
</td>
</tr>
</EditItemTemplate>
<InsertItemTemplate>
<asp:DynamicEntity ID="DynamicEntity3" runat="server" Mode="Insert" />
<tr class="td">
<td colspan="2">
<asp:LinkButton ID="LinkButton6" runat="server" CommandName="Insert" Text="Insert" />
<asp:LinkButton ID="LinkButton7" runat="server" CommandName="Cancel" Text="Cancel" CausesValidation="false" />
</td>
</tr>
</InsertItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:FormView>
<asp:EntityDataSource ID="DetailsDataSource" runat="server" EnableDelete="true" EnableInsert="true" EnableUpdate="true" />
<asp:QueryExtender ID="QueryExtender1" TargetControlID="DetailsDataSource" runat="server">
<asp:ControlFilterExpression ControlID="GridView1" />
</asp:QueryExtender>
</asp:Panel>
<%--code for details items --%>
<asp:Panel runat="server" ID="PanelItemDetails">
<asp:GridView ID="GridView2" runat="server"
DataSourceID="EntityDataSourceItemDetails" EnablePersistedSelection="True"
DataKeyNames="OrderNo"
AutoGenerateSelectButton="True"
AutoGenerateColumns="False"
AllowPaging="True" AllowSorting="True" OnDataBound="GridView2_DataBound"
OnRowEditing="GridView2_RowEditing" OnSelectedIndexChanging="GridView2_SelectedIndexChanging"
OnRowDeleted="GridView2_RowDeleted" OnRowUpdated="GridView2_RowUpdated"
OnRowCreated="GridView2_RowCreated" CssClass="DDGridView"
RowStyle-CssClass="td" HeaderStyle-CssClass="th" CellPadding="6">
<Columns>
<%--<asp:DynamicField DataField="tblCateringItemsDetail" HeaderText="Item" />--%>
<asp:BoundField DataField="Description" HeaderText="Description"
ReadOnly="True" SortExpression="Description" />
<asp:BoundField DataField="Quantity" HeaderText="Quantity" ReadOnly="True"
SortExpression="Quantity" />
<asp:BoundField DataField="TotalUnitCost" HeaderText="TotalUnitCost"
ReadOnly="True" SortExpression="TotalUnitCost" />
<asp:BoundField DataField="OrderNo" HeaderText="OrderNo" ReadOnly="True"
SortExpression="OrderNo" />
</Columns>
<HeaderStyle CssClass="th" />
<PagerStyle CssClass="DDFooter" />
<RowStyle CssClass="td" />
<SelectedRowStyle CssClass="DDSelected" />
<PagerTemplate>
<asp:GridViewPager ID="GridViewPager1" runat="server" />
</PagerTemplate>
<EmptyDataTemplate>
There are currently no items in this table.
</EmptyDataTemplate>
<SortedAscendingHeaderStyle BackColor="#DEDFF0" Font-Bold="True" />
<SortedDescendingHeaderStyle BackColor="#DEDFF0" Font-Bold="True" />
</asp:GridView>
<asp:QueryExtender ID="QueryExtender2" TargetControlID="EntityDataSourceItemDetails" runat="server">
<asp:CustomExpression
OnQuerying="OrdersQueryExtender_Querying" />
</asp:QueryExtender>
<asp:EntityDataSource ID="EntityDataSourceItemDetails" runat="server"
ConnectionString="name=cateringEntities"
DefaultContainerName="cateringEntities" EnableFlattening="False"
EntitySetName="vCateringOrdersAllDetails"
Select="it.[Description], it.[Quantity], it.[TotalUnitCost], it.[OrderNo]" ORDERBY="it.OrderNo]" >
</asp:EntityDataSource>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
C#代码：
protected void SelectOrder_Selected(object sender, EntityDataSourceSelectedEventArgs e)
{
IEnumerable<OrderItems> orderItem = e.Results.Cast<Order>();
foreach (Order o in orderItem)
{
customerId = c.Customer_Id;
}
}
protected void OrderQueryExtender_Querying(object sender, system.Web.UI.WebControls.Expressions.CustomExpressionEventArgs e)
{
e.Query = (from a in e.Query.Cast<Order>()
where a.OrderNo == orderNo
select a);
}
任何帮助将不胜感激。克莱尔