Localization in .NET Core 2 Web API - asp.net-core

Question

I've followed this guide for getting my localization to work with my validation. But either I've done something wrong, or it isn't supported.
I have a Controller:
[HttpPost]
public IActionResult Post([FromBody]Customer value)
{
if (ModelState.IsValid)
{
return Ok("Good job!");
}
return BadRequest(ModelState);
}
I register my localizations like so:
services.AddLocalization(options => options.ResourcesPath = "Resources");
services.AddMvc()
.AddViewLocalization(LanguageViewLocationExpanderFormat.Suffix)
.AddDataAnnotationsLocalization();
And my model:
public class Customer
{
[Required]
public string FirstName { get; set; }
[Required]
public string LastName { get; set; }
}
Here's my resx and my directory (all resx look alike):
What I want is to let the resource-file determine what message is passed for the propertyname when it's invalid.
Making this POST:
{
"firstname":"John"
}
Will currently return:
{
"LastName": [
"The LastName field is required."
]
}
Since I created a Resource for the Customer model I want the result to return this:
{
"LastName": [
"The Surname field is required."
]
}
I know I can use Display like this:
[Display(ResourceType = typeof(Models_Customer), Name = "FirstName")]
...but I thought that the entire point of naming the resource-files based on the model was to avoid it.

Answer 1

I have the same problem. But I guess, it works only with resx filnames like this:
Models.Customer.en-GB.resx
I tried it like you but this file name works only with culture region information.
Greeds
P.S.: I'm open for a solution like Models.Customer.en.resx