Using MVC 5 I need to localize an ErrorMessage for a DataAnnotation attributes. I receive the following error
ERROR
An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type
In model
[Compare("Password", ErrorMessage = Resources.Account_Register_ConfirmPasswordErrorMessage)]
public string ConfirmPassword { get; set; }
Any idea how to fix it?
Here's a detailed explanation on how to do this:
You add appropriate culture resx files to conventional folders, and tell the DA engine to look through them:
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc()
.AddDataAnnotationsLocalization(options => {
options.DataAnnotationLocalizerProvider = (type, factory) =>
factory.Create(typeof(SharedResource));
});
}
So for this model:
public class RegisterViewModel
{
[Required(ErrorMessage = "The Email field is required.")]
[EmailAddress(ErrorMessage = "The Email field is not a valid email address.")]
[Display(Name = "Email")]
public string Email { get; set; }
}
You'd add a resx file in one of the following locations:
For non-ASP.NET environments such as WPF, WinForms or others, see this answer.