區分GET方法中的ASP.NET Web API包含查詢字符串

Question

我有一個ASP.NET網頁API包含以下get方法：

[RoutePrefix("api/contact")] 
public class ContactController : ApiController 
{ 
    private ContactContext db = new ContactContext(); 

    public IEnumerable<Contact> Get() 
    { 
     return db.Contacts.AsEnumerable(); 
    } 



    [Route("{id:int}")] 
    public Contact Get(int id) 
    { 
     var result = db.Contacts.Find(id); 
     if (result == null) 
     { 


      throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound)); 
     } 
     return result; 
    } 

    public IEnumerable<Contact> GetContacts([FromUri]Filter filter) 
    { 
     return db.Contacts.Where(c => c.DepartmentId == filter.DepartmentId && c.City == filter.City).ToList(); 
    } 
} 

在功能public IEnumerable<Contact> GetContactsfilter([FromUri]Filter filter) DepartementId &市在查詢字符串像

localhost:12345/api/Contact?DepartmentId=2&city=Mumbai 

我的問題是我如何爲查詢添加屬性路由，因爲 目前它不能區分Get Methods和返回錯誤

{"Message":"An error has occurred.","ExceptionMessage":"Multiple actions were found that match the request: \r\nSystem.Collections.Generic.IEnumerable`1[MyFirstWebApi.Models.Contact] Get() on type MyFirstWebApi.Controllers.ContactController\r\nSystem.Collections.Generic.IEnumerable`1[MyFirstWebApi.Models.Contact] GetContacts(MyFirstWebApi.Models.Filter) on type MyFirstWebApi.Controllers.ContactController","ExceptionType":"System.InvalidOperationException","StackTrace":" at System.Web.Http.Controllers.ApiControllerActionSelector.ActionSelectorCacheItem.SelectAction(HttpControllerContext controllerContext)\r\n at System.Web.Http.Controllers.ApiControllerActionSelector.SelectAction(HttpControllerContext controllerContext)\r\n at System.Web.Http.ApiController.ExecuteAsync(HttpControllerContext controllerContext, CancellationToken cancellationToken)\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsyncCore(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.d__0.MoveNext()"} 

我試圖添加路由屬性來獲取方法，其中包含id但沒有奏效。

Answer 1

屬性路由或常規路由不支持模板中的查詢參數。相反，你可以修改你的控制器只有兩個動作，如下所示：

// Here if no DepartmentId or City are provided, then the 'filter' parameter would be null 
[Route] 
public IEnumerable<Contact> GetContacts([FromUri]Filter filter) 

[Route("{id:int}")] 
public Contact Get(int id)