I use OpenAPI (Swagger) in a .NET Core project and when using multiple methods that have similar get requests, I encounter "Microsoft.AspNetCore.Routing.Matching.AmbiguousMatchException: The request matched multiple endpoints." error during runtime. I look at several pages on the web and SO and tried to apply the workarounds like The request matched multiple endpoints but why?, but it does not fix the problem. Here are the API methods and route definitions that I use.
[Route("get", Name="get")]
public IEnumerable<DemoDto> Get()
{
//
}
[Route("get/{id}", Name="getById")]
public DemoDto GetById(int id)
{
//
}
[Route("get/{query}", Name="getWithPagination")]
public IEnumerable<DemoDto> GetWithPagination(DemoQuery query)
{
//
}
I use Name property in order to fix the problem but not solved. Any idea to make changes on the routes to differentiate Get() and GetWithPagination()?
You have two endpoints with equals routes:
get/{id} and get/{query}.
If you write in browser line: get/123, the system can't understand what route to use, because they have the same pattern.
You need to distinguish them and I suggest you use restful style for routes, like:
item/{id},
items?{your query}
[Route("get/{query}", Name="getWithPagination")]
This doesn't make sense. DemoQuery is an object, it can't be represented by a single part of a url. You can tell the ModelBinder to build your object from multiple query parameters, though.
The routing engine is getting this route confused with the [Route("get/{id}", Name="getById")] route. They both appear to match get/blah.
In addition to fixing your DemoQuery route, try adding a route constraint on the id route -
[Route("get/{id:int}", Name="getById")]
to better help the engine.
To get DemoQuery to work, assume it looks something like:
public class DemoQuery
{
public string Name { get; set; }
public int Value { get; set; }
}
Then change your action to
[Route("getPaged/{query}", Name="getWithPagination")]
public IEnumerable<DemoDto> GetWithPagination([FromQuery] DemoQuery query)
and call then endpoint like /getPaged?name=test&value=123. And the ModelBinder should build your object for you.
ASP.NET Web API 2 supports a new type of routing. Offical Doc
Route constraints let you restrict your parameters type and matched with these types (int, string, even date etc). The general syntax is "{parameter:constraint}"
[Route("users/{id:int}")]
public User GetUserById(int id) { ... }
[Route("users/{name}")]
public User GetUserByName(string name) { ... }
I tested at API;
//match : api/users/1
[HttpGet("{id:int}")]
public IActionResult GetUserById(int id){ ... }
//match : api/users/gokhan
[HttpGet("{name}")]
public IActionResult GetUserByName(string name){ ... }
i'm working with an API that i didn't made and there's no documentation about it, i have this class and method
[Route("api/[controller]")]
[ApiController]
public class SearchController : ControllerBase
{
[Route("[action]")]
[HttpGet]
public async Task<int> someMethod([FromQuery] QueryObject query)
{
//some logic
}
and this is my query object
public QueryObject
{
public int id {get; set;}
}
but i can't get to the breakpoint in the controller, i'm not quite sure how the url is suppose to be
Make a get request to: {the API's base url}/api/Search/{method name}
if u chose the mvc api project so it works with actions methods.
For example ...api/[controllername]/action_method
Other things are just classic C#
My bad, i'm kind of new to API, i haven't used before the Route("[action]")
so the correct url was localhost:0000/api/search/someMethod?id=1
We are using .NET Core to build a Web API. We need to support "GetBy" functionality, e.g. GetByName, GetByType, etc. but the issue we are running into is how to depict this through routes in a Restful way as well as the method overloading not properly working with how we think the routes should be. We are using MongoDB so our IDs are strings.
I'm assuming our routes should be something like this:
/api/templates?id=1
/api/templates?name=ScienceProject
/api/templates?type=Project
and the issue is that all our methods in our controller have a single string parameter and isn't properly mapped. Should the routes me different or is there a way to properly map these routes to the proper method?
If the parameters are mutually exclusive, i.e. you only search by name or type but not by name and type, then you can have the parameter be a part of the path instead of the query-params.
Example
[Route("templates")]
public class TemplatesController : Controller
{
[HttpGet("byname/{name}")]
public IActionResult GetByName(string name)
{
return Ok("ByName");
}
[HttpGet("bytype/{type}")]
public IActionResult GetByType(string type)
{
return Ok("ByType");
}
}
This example would lead to routes like:
/api/templates/byname/ScienceProject
/api/templates/bytype/Project
If there parameters are not mutually eclusive then you should do it like suggested in the answer by Fabian H.
You can make a TemplatesController with a single get method, that can take all the arguments.
[Route("api/templates")]
public class TemplatesController : Controller
{
[HttpGet]
public IActionResult Get(int? id = null, string name = null, string type = null)
{
// now handle you db stuff, you can check if your id, name, type is null and handle the query accordingly
return Ok(queryResult);
}
}
I am trying to add a Get() function in a MVC 6 (Asp .Net 5) Web Api to pass a configuration option as a query string. Here are the two functions that I already have:
[HttpGet]
public IEnumerable<Project> GetAll()
{
//This is called by http://localhost:53700/api/Project
}
[HttpGet("{id}")]
public Project Get(int id)
{
//This is called by http://localhost:53700/api/Project/4
}
[HttpGet()]
public dynamic Get([FromQuery] string withUser)
{
//This doesn't work with http://localhost:53700/api/Project?withUser=true
//Call routes to first function 'public IEnumerable<Project> GetAll()
}
I've tried several different ways to configure the routing, but MVC 6 is light on documentation. What I really need is a way to pass some configuration options to the list of Projects for sorting, custom filtering etc.
You can't have two [HttpGet]s with the same template in a single controller. I'm using asp.net5-beta7 and in my case it even throws the following exception:
Microsoft.AspNet.Mvc.AmbiguousActionException
Multiple actions matched. The following actions matched route data and had all constraints satisfied:
The reason for this is that [From*] attributes are meant for binding, not routing.
The following code should work for you:
[HttpGet]
public dynamic Get([FromQuery] string withUser)
{
if (string.IsNullOrEmpty(withUser))
{
return new string[] { "project1", "project2" };
}
else
{
return "hello " + withUser;
}
}
Also consider using Microsoft.AspNet.Routing.IRouteBuilder.MapRoute() instead of attribute routing. It may give you more freedom defining the routes.
Accessing the query string is very doable by using either the RESTful routing conventions (enforced by ASP.NET 5 / MVC 6 by default) or by defining custom routes, as explained in this answer.
Here's quick example using custom, attribute-based routes:
[HttpGet("GetLatestItems/{num}")]
public IEnumerable<string> GetLatestItems(int num)
{
return new string[] { "test", "test2" };
}
For more info about custom routing, read the following article on my blog.
I'm curious to see if you can overload controller methods in ASP.NET MVC. Whenever I try, I get the error below. The two methods accept different arguments. Is this something that cannot be done?
The current request for action 'MyMethod' on controller type 'MyController' is ambiguous between the following action methods:
You can use the attribute if you want your code to do overloading.
[ActionName("MyOverloadedName")]
But, you'll have to use a different action name for the same http method (as others have said). So it's just semantics at that point. Would you rather have the name in your code or your attribute?
Phil has an article related to this: http://haacked.com/archive/2008/08/29/how-a-method-becomes-an-action.aspx
Yes. I've been able to do this by setting the HttpGet/HttpPost (or equivalent AcceptVerbs attribute) for each controller method to something distinct, i.e., HttpGet or HttpPost, but not both. That way it can tell based on the type of request which method to use.
[HttpGet]
public ActionResult Show()
{
...
}
[HttpPost]
public ActionResult Show( string userName )
{
...
}
One suggestion I have is that, for a case like this, would be to have a private implementation that both of your public Action methods rely on to avoid duplicating code.
Here's something else you could do... you want a method that is able to have a parameter and not.
Why not try this...
public ActionResult Show( string username = null )
{
...
}
This has worked for me... and in this one method, you can actually test to see if you have the incoming parameter.
Updated to remove the invalid nullable syntax on string and use a default parameter value.
No,No and No. Go and try the controller code below where we have the "LoadCustomer" overloaded.
public class CustomerController : Controller
{
//
// GET: /Customer/
public ActionResult LoadCustomer()
{
return Content("LoadCustomer");
}
public ActionResult LoadCustomer(string str)
{
return Content("LoadCustomer with a string");
}
}
If you try to invoke the "LoadCustomer" action you will get error as shown in the below figure.
Polymorphism is a part of C# programming while HTTP is a protocol. HTTP does not understand polymorphism. HTTP works on the concept's or URL and URL can only have unique name's. So HTTP does not implement polymorphism.
In order to fix the same we need to use "ActionName" attribute.
public class CustomerController : Controller
{
//
// GET: /Customer/
public ActionResult LoadCustomer()
{
return Content("LoadCustomer");
}
[ActionName("LoadCustomerbyName")]
public ActionResult LoadCustomer(string str)
{
return Content("LoadCustomer with a string");
}
}
So now if you make a call to URL "Customer/LoadCustomer" the "LoadCustomer" action will be invoked and with URL structure "Customer/LoadCustomerByName" the "LoadCustomer(string str)" will be invoked.
The above answer i have taken from this codeproject article --> MVC Action overloading
To overcome this problem you can write an ActionMethodSelectorAttribute that examines the MethodInfo for each action and compares it to the posted Form values and then rejects any method for which the form values don't match (excluding the button name, of course).
Here's an example:- http://blog.abodit.com/2010/02/asp-net-mvc-ambiguous-match/
BUT, this isn't a good idea.
As far as I know you can only have the same method when using different http methods.
i.e.
[AcceptVerbs("GET")]
public ActionResult MyAction()
{
}
[AcceptVerbs("POST")]
public ActionResult MyAction(FormResult fm)
{
}
I have achieved this with the help of Attribute Routing in MVC5. Admittedly I am new to MVC coming from a decade of web development using WebForms, but the following has worked for me. Unlike the accepted answer this allows all the overloaded actions to be rendered by the same view file.
First enable Attribute Routing in App_Start/RouteConfig.cs.
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapMvcAttributeRoutes();
routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);
}
}
Optionally decorate your controller class with a default route prefix.
[RoutePrefix("Returns")]
public class ReturnsController : BaseController
{
//.......
Then decorate your controller actions that overload each other with a common route and parameters to suit. Using type constrained parameters you can use the same URI format with IDs of different types.
[HttpGet]
// Returns
public ActionResult Index()
{
//.....
}
[HttpGet]
[Route("View")]
// Returns/View
public ActionResult View()
{
// I wouldn't really do this but it proves the concept.
int id = 7026;
return View(id);
}
[HttpGet]
[Route("View/{id:int}")]
// Returns/View/7003
public ActionResult View(int id)
{
//.....
}
[HttpGet]
[Route("View/{id:Guid}")]
// Returns/View/99300046-0ba4-47db-81bf-ba6e3ac3cf01
public ActionResult View(Guid id)
{
//.....
}
Hope this helps and is not leading somebody down the wrong path. :-)
You could use a single ActionResult to deal with both Post and Get:
public ActionResult Example() {
if (Request.HttpMethod.ToUpperInvariant() == "GET") {
// GET
}
else if (Request.HttpMethod.ToUpperInvariant() == "POST") {
// Post
}
}
Useful if your Get and Post methods have matching signatures.
I've just come across this question and, even though it's quite old now, it's still very relevant. Ironically, the one correct comment in this thread was posted by a self-confessed beginner in MVC when he wrote the post. Even the ASP.NET docs are not entirely correct. I have a large project and I successfully overload action methods.
If one understands routing, beyond the simple {controller}/{action}/{id} default route pattern, it might be obvious that controller actions can be mapped using any unique pattern. Someone here talked about polymorphism and said: "HTTP does not understand polymorphism", but routing has nothing to do with HTTP. It is, simply put, a mechanism for string pattern matching.
The best way to make this work is to use the routing attributes, for example:
[RoutePrefix("cars/{country:length(3)}")]
public class CarHireController
{
[Route("{location}/{page:int=1}", Name = "CarHireLocation")]
public ActionResult Index(string country, string location, int page)
{
return Index(country, location, null, page);
}
[Route("{location}/{subLocation}/{page:int=1}", Name = "CarHireSubLocation")]
public ActionResult Index(string country, string location, string subLocation, int page)
{
//The main work goes here
}
}
These actions will take care of urls like /cars/usa/new-york and /cars/usa/texas/dallas, which will map to the first and second Index actions respectively.
Examining this example controller it's evident that it goes beyond the default route pattern mentioned above. The default works well if your url structure exactly matches your code naming conventions, but this is not always the case. Code should be descriptive of the domain, but urls often need to go further because their content should be based on other criteria, such as SEO requirements.
The benefit of the default routing pattern is that it automatically creates unique routes. This is enforced by the compiler since urls will match unique controller types and members. Rolling your own route patterns will require careful thought to ensure uniqueness and that they work.
Important note The one drawback is that using routing to generate urls for overloaded actions does not work when based on an action name, e.g., when using UrlHelper.Action. But it does work if one uses named routes, e.g., UrlHelper.RouteUrl. And using named routes is, according to well respected sources, the way to go anyhow (http://haacked.com/archive/2010/11/21/named-routes-to-the-rescue.aspx/).
Good luck!
You can use [ActionName("NewActionName")] to use the same method with a different name:
public class HomeController : Controller
{
public ActionResult GetEmpName()
{
return Content("This is the test Message");
}
[ActionName("GetEmpWithCode")]
public ActionResult GetEmpName(string EmpCode)
{
return Content("This is the test Messagewith Overloaded");
}
}
I needed an overload for:
public ActionResult Index(string i);
public ActionResult Index(int groupId, int itemId);
There were few enough arguments where I ended up doing this:
public ActionResult Index(string i, int? groupId, int? itemId)
{
if (!string.IsNullOrWhitespace(i))
{
// parse i for the id
}
else if (groupId.HasValue && itemId.HasValue)
{
// use groupId and itemId for the id
}
}
It's not a perfect solution, especially if you have a lot of arguments, but it works well for me.
I have faced same issue in my application too. Without Modifiyig any Method information, I have provided [ActionName("SomeMeaningfulName")] on Action head. issue resolved
[ActionName("_EmployeeDetailsByModel")]
public PartialViewResult _EmployeeDetails(Employee model)
{
// Some Operation
return PartialView(model);
}
}
[ActionName("_EmployeeDetailsByModelWithPagination")]
public PartialViewResult _EmployeeDetails(Employee model,int Page,int PageSize)
{
// Some Operation
return PartialView(model);
}
Create the base method as virtual
public virtual ActionResult Index()
Create the overridden method as override
public override ActionResult Index()
Edit: This obviously applies only if the override method is in a derived class which appears not to have been the OP's intention.
I like this answer posted in another thread
This is mainly used if you inherit from another controller and want to override an acction from the base controller
ASP.NET MVC - Overriding an action with differing parameters
There is only one public signature allowed for each controller method. If you try to overload it, it will compile, but you're getting the run-time error you've experienced.
If you're not willing to use different verbs (like the [HttpGet] and [HttpPost] attributes) to differentiate overloaded methods (which will work), or change the routing, then what remains is that you can either provide another method with a different name, or you can dispatch inside of the existing method. Here's how I did it:
I once came into a situation where I had to maintain backwards compatibility. The original method expected two parameters, but the new one had only one. Overloading the way I expected did not work because MVC didn't find the entry point any more.
To solve that, I did the following:
Changed the 2 overloaded action methods from public to private
Created one new public method which contained "just" 2 string parameters. That one acted as a dispatcher, i.e.:
public ActionResult DoSomething(string param1, string param2)
{
if (string.IsNullOrEmpty(param2))
{
return DoSomething(ProductName: param1);
}
else
{
int oldId = int.Parse(param1);
return DoSomething(OldParam: param1, OldId: oldId);
}
}
private ActionResult DoSomething(string OldParam, int OldId)
{
// some code here
return Json(result);
}
private ActionResult DoSomething(string ProductName)
{
// some code here
return Json(result);
}
Of course, this is a hack and should be refactored later. But for the time being, it worked for me.
You can also create a dispatcher like:
public ActionResult DoSomething(string action, string param1, string param2)
{
switch (action)
{
case "update":
return UpdateAction(param1, param2);
case "remove":
return DeleteAction(param1);
}
}
You can see, that UpdateAction needs 2 parameters, while DeleteAction just needs one.
Sorry for the delay. I was with the same problem and I found a link with good answers, could that will help new guys
All credits for BinaryIntellect web site and the authors
Basically, there are four situations: using differents verbs, using routing, overload marking with [NoAction] attribute and change the action attribute name with [ActionName]
So, depends that's your requiriments and your situation.
Howsoever, follow the link:
Link:
http://www.binaryintellect.net/articles/8f9d9a8f-7abf-4df6-be8a-9895882ab562.aspx
This answer for those who struggling with the same issue. You can
implement your own custom filter based on
ActionMethodSelectorAttribute. Here I found the best solution
for solving your question. Works fine on .net 5 project.
If you try to implement the same logic as was in web api controllers then use Microsoft.AspNetCore.Mvc.WebApiCompatShim. This nuget package provides compatibility in ASP.NET Core MVC with ASP.NET Web API 2 to simplify migration of existing Web API implementations. Please check this answer but consider that
starting with ASP.NET Core 3.0, the Microsoft.AspNetCore.Mvc.WebApiCompatShim package is no longer available.
If this is an attempt to use one GET action for several views that POST to several actions with different models, then try add a GET action for each POST action that redirects to the first GET to prevent 404 on refresh.
Long shot but common scenario.