1

我有一个实体框架层，并从该层扩展了一个类。代码如下：

public partial class FeatureMaster : EntityObject
{
    public string ParentFeatureName
    {
        get
        {
            return (from r in Global.dc.FeatureMasters
                    where r.FeatureId == FeatureParentId
                    select r).SingleOrDefault().FeatureName;
        }
        set
        {
            FeatureParentId = (from r in Global.dc.FeatureMasters
                               where r.FeatureName == value
                               select r).SingleOrDefault().FeatureId;
            ReportPropertyChanged(("ParentFeatureName"));
            ReportPropertyChanged(("FeatureParentId"));
        }
    }
}

现在我希望在我的 ASP.NET 页面中使用它。我的 ASP.NET 页面的代码是：

    <%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true"
    CodeBehind="ListFeatureMaster.aspx.cs" Inherits="Backend.ListFeatureMaster" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="cpMain" runat="server">
    <asp:GridView ID="grdRecords" runat="server" AllowPaging="True" AllowSorting="True"
        AutoGenerateColumns="False" DataKeyNames="FeatureId" DataSourceID="EntityDataSource1">
        <Columns>
            <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" />
            <asp:BoundField DataField="FeatureId" HeaderText="FeatureId" ReadOnly="True" SortExpression="FeatureId" />
            <asp:BoundField DataField="FeatureName" HeaderText="FeatureName" SortExpression="FeatureName" />
            <asp:BoundField DataField="FeatureParentId" HeaderText="FeatureParentId" SortExpression="FeatureParentId" />
            <asp:BoundField DataField="FeatureDescription" HeaderText="FeatureDescription" SortExpression="FeatureDescription" />
            <asp:TemplateField HeaderText="ParentFeatureName" SortExpression="ParentFeatureName">
                <EditItemTemplate>
                    <asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="EntityDataSource1"
                        AppendDataBoundItems="true" DataTextField="ParentFeatureName" DataValueField="ParentFeatureName"
                        SelectedValue='<%# Bind("ParentFeatureName") %>'>
                    </asp:DropDownList>
                </EditItemTemplate>
                <ItemTemplate>
                    <asp:Label ID="Label1" runat="server" Text='<%# Eval("ParentFeatureName") %>'></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>
    <asp:EntityDataSource ID="EntityDataSource1" runat="server" ConnectionString="name=BackendEntities"
        DefaultContainerName="BackendEntities" EnableFlattening="False" EntitySetName="FeatureMasters"
        EntityTypeFilter="FeatureMaster" EnableDelete="True" EnableUpdate="True">
    </asp:EntityDataSource>
        <asp:EntityDataSource ID="EntityDataSource2" runat="server" ConnectionString="name=BackendEntities"
        DefaultContainerName="BackendEntities" EnableFlattening="False" EntitySetName="FeatureMasters"
        EntityTypeFilter="FeatureMaster" EnableDelete="True" EnableUpdate="True">
    </asp:EntityDataSource>
</asp:Content>

问题是当我执行这段代码时，它在第一次加载和导航时运行良好，但是当我尝试更新记录时，我得到了错误。请帮我解决同样的问题。

错误信息说：

A property named 'ParentFeatureName' was not found on the entity during an insert, update, or delete operation. Check to ensure that properties specified as binding expressions are available to the data source.
4

2 回答 2

1

我认为问题在于您没有将自定义属性附加到您的实体，然后保存它。您可以看看将客户属性添加到实体类

希望能帮助到你。

于 2013-04-19T13:15:39.077 回答
0

我得到了解决方案。

我更改了 GridView 的定义并向其中添加了 OnRowUpdating 事件。ASPX 页面代码现在看起来像：

<asp:GridView ID="grdRecords" runat="server" AllowPaging="True" AllowSorting="True"
    AutoGenerateColumns="False" DataKeyNames="FeatureId" DataSourceID="EntityDataSource1" OnRowUpdating="grdRecords_RowUpdating">

在我的 .aspx.cs 文件中，我添加了事件处理程序的代码。相同的代码如下所示：

        protected void grdRecords_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        int primaryKey = Convert.ToInt32(grdRecords.DataKeys[e.RowIndex].Value);

        FeatureMaster existingRecord = Global.dc.FeatureMasters.First(r => r.FeatureId == primaryKey);
        existingRecord.FeatureName = e.NewValues["FeatureName"].ToString();
        existingRecord.ParentFeatureName = ((DropDownList)(grdRecords.Rows[e.RowIndex].FindControl("DropDownList1"))).SelectedValue.ToString();
        existingRecord.FeatureDescription = e.NewValues["FeatureDescription"].ToString();

        Global.dc.SaveChanges();

        grdRecords.EditIndex = -1;

        e.Cancel = true;
    }
于 2013-04-21T10:18:07.950 回答