Ambiguousmatchexception: the request matched multiple endpoints. Matches:

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I really like the progress am making learning ASP.NET. Yesterday I started off and learnt that you need to have two folders in your ASP project where one(Pages) contains the ASP Razor pages and the other one(wwwroot) contains the styling files for the razor pages. I also learnt that the entire behavior of the page displayed to the user is controlled by the code behind file in the startup C# code file, like you cannot be able to use bootstrap and custom css styles until you check the line

C#

app.UseStaticFiles();

Now I have created a bootstrap form with the fields name and description with inputs for each inside a modal and then gave them asp identifiers so that the model file can receive these values when the form post action is called. I created a Models folder and added a new class file called IndexModel and then declared two getters and setters for the name and query called Name and Description respectively. Check the definitions for all the relevant files in the code block section below.

What I have tried:

This is my IndexModel.cs file

C#

public class IndexModel
  {
      public string Name { get; set; }
      public string Description { get; set; }
      //receive the values entered by the user through the onpost method
      public void OnPost()
      {
          Name = Name;
          Description = Description;

      }
  }

This is the form

HTML

<form onsubmit="return false;" action="post" id="form">
 <div class="form-group">
   <label for="name">Name</label>
     <input type="text" class="form-control" id="name" placeholder="Enter your name" asp-for="Name">
      </div>
      <div class="form-group">
  <label for="query">Query</label>
 <textarea class="form-control" id="query" style="margin-top:20px" rows="5" placeholder="Enter your query" asp-for="Description"></textarea>
                            </div>
     
</form>

I have handled the user input in my JavaScript file when I try to call this line

JavaScript

//means everything is okay, now pass the values entered to the ASP models
form. Submit();

I get the error

AmbiguousMatchException: The request matched multiple endpoints. Matches:

Wht is that error and how can I resolve this?

Posted 19-Jun-23 21:59pm

Tim the Gamer

Updated 19-Jun-23 22:12pm

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1 solution

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Graeme_Grant · Accepted Answer · 2023-06-19T22:12:00

Solution 1

Normally, this means that you have more than one route with the same POST signature, ie: same params.

Also, your Form properties are not correct. Refer to: Tag Helpers in forms in ASP.NET Core | Microsoft Learn[^]. According to the sample in the link provided, when the page is inspected, it should look like:

HTML

<form method="post" action="/Demo/Register">
    <!-- Input and Submit elements -->
    <input name="__RequestVerificationToken" type="hidden" value="<removed for brevity>">
</form>

UPDATE

Okay, It has been established that you are creating a WebForms ASP.NET Web App, Also known as a Razor Pages App[^].

Here is a good Tutorial to show you how to Post Data for this style of app: How to Submit (Post) Form in ASP.Net Core Razor Pages - YouTube[^].

UPDATE #2

For MVC[^], here is a tutorial for you: Handle Multiple Form Submit Buttons in ASP.NET Core MVC - ASP.NET 6 MVC - YouTube[^] and here is a website dedicated to teaching you MVC: The ASP.NET Core MVC Tutorial[^]

Posted 19-Jun-23 22:12pm

Graeme_Grant

Updated 19-Jun-23 23:25pm

v4

Comments

Tim the Gamer 20-Jun-23 4:15am

Yes, I got the action wrong. The action should point to the file that should process the form input, then the method should be post. Let me try and change those and see if it will work

Graeme_Grant 20-Jun-23 4:24am

~~If this helped, which it appears to have, please mark the solution as accepted so that others are aware.~~ It appears that there is no back end to handle the POST data. A link is provided below that explains how to make a MVC ASP.Net Core app.

Tim the Gamer 20-Jun-23 4:25am

Let me inspect the tutorials in the attached link more because it's still throwing the ambiguous match exception error

Graeme_Grant 20-Jun-23 4:31am

Only client-side code posted, no server-side code, so hard to debug from here.

Check the route both on the client and server. Also check your routing configuration and if any controller methods have the same params. You may have duplicate routes defined. Lastly, make sure that you have tagged the controller method as POST.

Tim the Gamer 20-Jun-23 4:32am

I do not have any controller classes or folder in my project. Do I need a controller for a form?

Graeme_Grant 20-Jun-23 4:33am

What are you POSTing to??? How are you processing the POSTed data from the Form?

Tim the Gamer 20-Jun-23 4:34am

To the model class, thought I could receive the data in the form to the model class called Index Model?

Graeme_Grant 20-Jun-23 4:35am

Does not work like that. You need an endpoint to post the data to. The data posted is contained by the model or method params of the endpoint handler.

Graeme_Grant 20-Jun-23 4:37am

Start here: Get started with ASP.NET Core MVC | Microsoft Learn[^]

Tim the Gamer 20-Jun-23 4:47am

I have learnt that we need a controller and a method within that controller for handling the form data

Tim the Gamer 20-Jun-23 4:48am

The address on the URL when the error is thrown is
localhost:7119/post?

Graeme_Grant 20-Jun-23 4:59am

Quick question, is this a WebForms or MVC (Model-View-Controller) ASP.NET Core Web App? I made the assumption it was MVC.

WebForms works differently. The IndexModel needs to inherit the PageModel which is missing from your sample IndexModel.

Tim the Gamer 20-Jun-23 5:01am

It is asp. NET core web app

Graeme_Grant 20-Jun-23 5:03am

WebForms or MVC? both are ASP.NET Core Web Apps, but both work differently.

Graeme_Grant 20-Jun-23 5:14am

I have updated my answer for you. This should solve your issue.

Graeme_Grant 20-Jun-23 4:47am

I believe the issue has been identified and resolved. An endpoint route, either minimal API or MVC Controller is required for the POST data to be process. Please mark the solution as accepted. Thank you.

Tim the Gamer 20-Jun-23 5:03am

Let me first create a new controller then create a method that should receive the data and write a to a text file so I can accept your solution

Tim the Gamer 20-Jun-23 5:09am

I have added a new controller called Form Controller inside the Controllers folder, I have defined a method callwd IActionResult Get Action, what should I return from this method?

Graeme_Grant 20-Jun-23 5:14am

I have updated my answer for you. This should solve your issue.

Tim the Gamer 20-Jun-23 5:19am

Can you update your answer to include the controller and what object I should return from the IActionResult method for the form data to be processed accordingly. It would mean a lot to me and I would accept it

Graeme_Grant 20-Jun-23 5:21am

So you want to switch to MVC?

Tim the Gamer 20-Jun-23 5:23am

Yeah but should I return a string like "Data successfully received by the controller" and then point my form to this controller?

Graeme_Grant 20-Jun-23 5:25am

Done.

Tim the Gamer 20-Jun-23 5:27am

I did and the error is not shown but I get the http error 400 this page is not working, why isn't it returning the string I returned in my Get Action method?

Graeme_Grant 20-Jun-23 5:42am

In program.cs did you enable for MVC? Create a sample MVC version and look at how it is configured. The details are in the Microsoft Learn links provided.

Tim the Gamer 20-Jun-23 5:43am

How do I programmatically enable mvc from Program.cs?

Graeme_Grant 20-Jun-23 5:50am

here is the default:

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllersWithViews();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.Run();

Richard Deeming 20-Jun-23 5:46am

"... a WebForms ASP.NET Web App ..."

That's not going to confuse anyone at all! 🤣

WebForms is the ancient .NET Framework-only technology built around pages, views, viewstate, postbacks, etc. It has no place in a discussion about ASP.NET Core.

Graeme_Grant 20-Jun-23 5:50am

I did update and say Razor Pages ... I have heard MS still refers to it as WebForms, old or not.

Tim the Gamer 20-Jun-23 5:51am

So is there a way to add controllers to my current project and decorate them with either httpGet or httpPost to receive values from the web form?

Richard Deeming 20-Jun-23 5:52am

That would be a particularly bizarre choice on Microsoft's part.

Tim the Gamer 20-Jun-23 5:56am

Their technologies are creating millionaires and that's why I need to master the Microsoft Tech Stack no matter how difficult it seems. Let me try and add the MVC enabler in my file and see whether I will get something out of it

Dave Kreskowiak 20-Jun-23 9:34am

Their technologies are creating millionaires
BWHAHAHAHAHA! That was funny.

Tim the Gamer 20-Jun-23 6:14am

I will ask a new question

Tim the Gamer 20-Jun-23 6:17am

It is showing the http error 400 with this in the URL bar
https://localhost:7119/#

Ambiguousmatchexception: the request matched multiple endpoints. Matches:

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Ambiguousmatchexception: the request matched multiple endpoints. Matches:

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