ASP.Net WebAPI：如何使用IHttpActionResult而不是HttpResponseMessage

Question

我想使用IHttpActionResult而不是HttpResponseMessage 。 在下面的代碼中，我使用了HttpResponseMessage但在尋找一些指導方針如何重組下面的代碼以將IHttpActionResult與return Ok()和return NotFound();

請指導我如何重組下面的代碼，這樣我將能夠使用Ok()返回數據列表，同時告訴我在NotFound();找不到數據時如何返回錯誤消息NotFound();

[System.Web.Http.HttpGet, System.Web.Http.Route("UserAppointments/{email}")]
public System.Net.Http.HttpResponseMessage UserAppointments(string email = null)
{
    System.Net.Http.HttpResponseMessage retObject = null;

    if (!string.IsNullOrEmpty(email))
    {
        UserAppointmentService _appservice = new UserAppointmentService();
        IEnumerable<Entities.UserAppointments> app = _appservice.GetAppointmentsByEmail(email);

        if (app.Count() <= 0)
        {
            var message = string.Format("No appointment found for the user [{0}]", email);
            HttpError err = new HttpError(message);
            retObject = Request.CreateErrorResponse(System.Net.HttpStatusCode.NotFound, err);
            retObject.ReasonPhrase = message;
        }
        else
        {
            retObject = Request.CreateResponse(System.Net.HttpStatusCode.OK, app);
        }
    }
    else
    {
        var message = string.Format("No email provided");
        HttpError err = new HttpError(message);
        retObject = Request.CreateErrorResponse(System.Net.HttpStatusCode.NotFound, err);
        retObject.ReasonPhrase = message;

    }
    return retObject;
}

Answer 1

有兩種方法可以解決這個問題

第一個方法很簡單，只需更改返回類型並將HttpResponseMessage傳遞給ResponseMessage ，該方法返回一個IHttpActionResult派生類。

[HttpGet]
[Route("UserAppointments/{email}")]
public IHttpActionResult UserAppointments(string email = null) {
    HttpResponseMessage retObject = null;    
    if (!string.IsNullOrEmpty(email)) {
        UserAppointmentService _appservice = new UserAppointmentService();
        IEnumerable<Entities.UserAppointments> app = _appservice.GetAppointmentsByEmail(email);

        if (app.Count() <= 0) {
            var message = string.Format("No appointment found for the user [{0}]", email);
            HttpError err = new HttpError(message);
            retObject = Request.CreateErrorResponse(System.Net.HttpStatusCode.NotFound, err);
            retObject.ReasonPhrase = message;
        } else {
            retObject = Request.CreateResponse(System.Net.HttpStatusCode.OK, app);
        }
    } else {
        var message = string.Format("No email provided");
        HttpError err = new HttpError(message);
        retObject = Request.CreateErrorResponse(System.Net.HttpStatusCode.NotFound, err);
        retObject.ReasonPhrase = message;

    }
    return ResponseMessage(retObject);
}

替代方法是重構該方法，以遵循Asp.Net Web API 2文檔中的語法建議。

[HttpGet]
[Route("UserAppointments/{email}")]
public IHttpActionResult UserAppointments(string email = null) {
    if (!string.IsNullOrEmpty(email)) {
        var _appservice = new UserAppointmentService();
        IEnumerable<Entities.UserAppointments> app = _appservice.GetAppointmentsByEmail(email);
        if (app.Count() <= 0) {
            var message = string.Format("No appointment found for the user [{0}]", email);
            return Content(HttpStatusCode.NotFound, message);
        }
        return Ok(app);
    }
    return BadRequest("No email provided");
}

Web API 2中的參考操作結果

Answer 2

請嘗試以下操作：

[HttpGet("{email}")]
[Route("UserAppointments/{email}")]
public IHttpActionResult GetAppoinment(string email = null){
    if (!string.IsNullOrEmpty(email)){
        //Your business logic ...
        List<UserAppointment> app = new List<UserAppointment>();
        if (app.Count() <= 0)
            return Content(HttpStatusCode.NoContent, string.Format("No appointment found for the user [{0}]", email));
        else
            return Ok(app);
    } else {
        return BadRequest("No email provided");
    }
}

進一步閱讀：

• 返回HttpResponseMessage的最佳方法