如何在ASP.NET MVC的EF6中包含多个导航属性的导航属性，并支持即时加载？

// 定义实体类
public class Order
{
    public int OrderId { get; set; }
    public string OrderNumber { get; set; }
    public ICollection<OrderItem> OrderItems { get; set; }
}

public class OrderItem
{
    public int OrderItemId { get; set; }
    public string ProductName { get; set; }
    public decimal Price { get; set; }
    public int Quantity { get; set; }
    public int OrderId { get; set; }
    public Order Order { get; set; }
}

// 查询数据并包含多个导航属性的导航属性
using (var context = new YourDbContext())
{
    var orders = context.Orders
        .Include(o => o.OrderItems.Select(oi => oi.Order)) // 包含OrderItems导航属性，并加载Order导航属性
        .ToList();
}