OData Web Api控制器中带有$expand的NullReferenceException

环境：Net Core 3.1 Web Api，Microsoft.AspNetCore.OData 7.4.0-beta

我有一个ODataAPI控制器CustomerController，它工作正常，但$expand总是返回NullReferenceException。客户有一对多的联系人和地址

这是行动守则方法：

    [HttpGet]
    [ODataRoute]
    [EnableQuery]
    public IActionResult Get()
    {
        try
        {
            var customers = _context.Customers;

            _logger.LogInfo($"Returned {customers.Count()} customers from database.");

            return Ok(customers);
        }
        catch (Exception ex)
        {
            _logger.LogError($"Something went wrong inside Get customers action: {ex.Message}");
            return StatusCode(500, "Internal server error");
        }
    }

这是客户对象定义：

public class Customer : BaseEntity
{
    public Guid CustomerId { get; set; }

    [Required(ErrorMessage = "Name is required")]
    [StringLength(100, ErrorMessage = "Name can't be longer than 100 characters")]
    public string Name { get; set; }

    [StringLength(100, ErrorMessage = "Commercial name can't be longer than 100 characters")]
    public string CommercialName { get; set; }

    [Required(ErrorMessage = "Tax code is required")]
    [StringLength(25, ErrorMessage = "Tax code can't be longer than 25 characters")]
    public string TaxCode { get; set; }

    [StringLength(250, ErrorMessage = "Email can't be longer than 250 characters")]
    [EmailAddress]
    public string Email { get; set; }

    [StringLength(250, ErrorMessage = "Url can't be longer than 250 characters")]
    public string Url { get; set; }

    public ICollection<Contact> Contacts { get; set; }
    public ICollection<Address> Addresses { get; set; }
    public ICollection<Work> Works { get; set; }
}

我有另一个控制器，但是有一对一的关系，这个控制器可以很好地与$expand一起使用相同的代码执行方法

你知道什么是失败的吗？

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关于

我发现这是OData Web Api库版本的问题

这就是问题所在：

---

这是否回答了您的问题？抱歉，这是正确的url。。。

        // Table
        builder.ToTable("Customers");
        builder.HasKey(b => b.CustomerId);

        // Relationships
        builder.HasMany(b => b.Contacts)
            .WithOne(b => b.Customer)
            .HasForeignKey(b => b.CustomerId)
            .OnDelete(DeleteBehavior.Cascade);

        builder.HasMany(b => b.Addresses)
            .WithOne(b => b.Customer)
            .HasForeignKey(b => b.CustomerId)
            .OnDelete(DeleteBehavior.Cascade);