【C#】ADO .Net Entities Framework使用查詢語句時遇到的錯誤

XAML代碼:

<Window x:Class="WpfApplication72.MainWindow"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

        xmlns:local="clr-namespace:WpfApplication72"

        mc:Ignorable="d"

        Title="MainWindow" Height="350" Width="525">

    <Grid>

        <DataGrid x:Name="listBox" ItemsSource="{Binding}" />

    </Grid>

</Window>

隱藏代碼：

using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Imaging;

using System.Windows.Navigation;

using System.Windows.Shapes;

namespace WpfApplication72

{

    /// <summary>

    /// Interaction logic for MainWindow.xaml

    /// </summary>

    public partial class MainWindow : Window

    {

        private Formula1v2Entities data = new Formula1v2Entities();

        public MainWindow()

        {

            InitializeComponent();

            this.DataContext = collection;

        }

        public IEnumerable<object>collection

        {

            get

            {

                return (from r in data.Racers

                       select new

                       {

                         Id=r.Id,

                         FirstName=r.FirstName,

                         LastName=r.LastName,

                         Nationality=r.Nationality

                       }).ToList();

            }

        }

    }

}

在隱藏代碼中如果沒有ToList（）方法的話，運行程序會報如下的錯誤：

Additional information: Data binding directly to a store query (DbSet, DbQuery, DbSqlQuery, DbRawSqlQuery) is not supported. Instead populate a DbSet with data, for example by calling Load on the DbSet, and then bind to local data. For WPF bind to DbSet.Local. For WinForms bind to DbSet.Local.ToBindingList(). For ASP.NET WebForms you can bind to the result of calling ToList() on the query or use Model Binding,

for more information see http://go.microsoft.com/fwlink/?LinkId=389592.

參考鏈接：

https://www.devexpress.com/Support/Center/Question/Details/Q580427