Asp.net web api Api定义路由中的可选参数

在控制器端点的路由上定义可选参数的正确语法是什么

    [Route("customers/{customerId}/boats/{boatId}/bookings{contractId?}&{startDate?}&{endDate?}&{outOnly?}", Name = "GetBookingsByBoat")]
    [ResponseType(typeof (IEnumerable<BookingSummaryDTO>))]
    public IHttpActionResult Get(int customerId, int boatId, int? contractId, DateTime? startDate, DateTime? endDate, bool outOnly = false)
    {

我得到：

{"message":"The requested resource does not support http method 'GET'."}

非常感谢

这是解决方案：

    [Route("customers/{customerId}/boats/{boatId}/bookings", Name = "GetBookingsByBoat")]
    [ResponseType(typeof (IEnumerable<BookingSummaryDTO>))]
    public IHttpActionResult Get(int customerId, int boatId, int? contractId = null, DateTime? startDate = null, DateTime? endDate = null, bool outOnly = false)

    [Route("customers/{customerId}/boats/{boatId}/bookings", Name = "GetBookingsByBoat")]
    [ResponseType(typeof (IEnumerable<BookingSummaryDTO>))]
    public IHttpActionResult Get(int customerId, int boatId, int? contractId = null, DateTime? startDate = null, DateTime? endDate = null, bool outOnly = false)