Localization on data annotation and error validation messages in ASP.NET CORE 3.1

Question

How to localize data annotation and validation error messages in ASP.NET CORE 3.1

[Required(ErrorMessage = "something")]
                [StringLength(100, ErrorMessage = "The {0} must be at least {2} and at max {1} characters long.", MinimumLength = 6)]
                [DataType(DataType.Password)]
                [Display(Name = "Password")]
                public string Password { get; set; }

I use the standard implementation of resource files from the Microsoft documentation

services.AddLocalization(option => option.ResourcesPath = ProjectConstants.LanguageResourcesPath);

        services.AddControllersWithViews()
                .AddViewLocalization(
                    LanguageViewLocationExpanderFormat.Suffix,
                      option => option.ResourcesPath = "Resources")
                .AddDataAnnotationsLocalization();

My Resource Files structure

|-Resoures
|---Controllers
|---Views
|---Models

I am refactoring Identity Pages and can not showing standard error messages in two languages. This example in Microsoft docs does not work for me.. [https://docs.microsoft.com/en-us/aspnet/core/fundamentals/localization?view=aspnetcore-3.1#dataannotations-localization] Please someone help me

Where is your model?Make sure the naming of resource file is correct.You could set LogLevel to Debug in appsettings.Development.json and check the log when you submit the form. — Ryan
In addition to @XingZou answer, This tutorial and repository can help do localization faster. — LazZiya
Hi, there was a problem naming the resource and I found it, but it came up big. I get an error when I try to make the resource public "InvalidOperationException: Cannot retrieve property 'Name' because localization failed." And also I get an error in Visual Studio for resxcodegenerator "PublicResXFileCodeGenerator failed to produce an output for input file 'Resource.en-US.resx' but did not log a specific error." I tried my best and I can't fix it, has anyone encountered this problem? — Валентин Стоев

Ryan Ryan · Accepted Answer · 2019-12-31T04:14:55

For adding DataAnnotations localization on InputModel in default Identity Register Pages(located in /Areas/Identity/Pages/Account/Register.cshtml.cs),you need to name your resource file like

Areas.Identity.Pages.Account.RegisterModel+InputModel.en-US.resx

For any nested model in PageModel, you need to use + instead of .

Localization on data annotation and error validation messages in ASP.NET CORE 3.1

1 Answers