ASP.NET Identity AllowOnlyAlphanumericUserNames - asp.net

Question

Can someone please help me how can i use special characters in ASP.Net identity?
The problem is that my users cannot register with special characters: č,ć,š,ž,đ.
When you try to enter this characters in registration, i get following error:
User name Krešo is invalid, can only contain letters or digits.
Where and how can i change this.
Here is the code:
using Microsoft.AspNet.Identity;
using Microsoft.Owin.Security;
using Microsoft.AspNet.Identity.EntityFramework;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class Pages_Account_Register : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnPrijava_Click(object sender, EventArgs e)
{
UserStore<IdentityUser> userStore = new UserStore<IdentityUser>();
userStore.Context.Database.Connection.ConnectionString =
System.Configuration.ConfigurationManager.ConnectionStrings["SeminariConnectionString3"].ConnectionString;
UserManager<IdentityUser> manager = new UserManager<IdentityUser>(userStore);
IdentityUser user = new IdentityUser();
user.UserName = txtKorisnickoIme.Text;
if(txtLozinka.Text == txtPotvrdaLozinke.Text)
{
try
{
IdentityResult result = manager.Create(user, txtLozinka.Text);
if(result.Succeeded)
{
var authenticationManager = HttpContext.Current.GetOwinContext().Authentication;
var userIdentity = manager.CreateIdentity(user, DefaultAuthenticationTypes.ApplicationCookie);
authenticationManager.SignIn(new AuthenticationProperties(), userIdentity);
Response.Redirect("Pocetna.aspx");
}
else
{
litStatus.Text = result.Errors.FirstOrDefault();
}
}
catch (Exception ex)
{
litStatus.Text = ex.ToString();
}
}
else
{
litStatus.Text = "Lozinke moraju biti identične.";
}
}
}

Answer 1

You should be able to change this behaviour as follows:
var manager = new UserManager<IdentityUser>(userStore); // existing code
var validator = manager.UserValidator as UserValidator<ApplicationUser>;
if (validator != null) validator.AllowOnlyAlphanumericUserNames = false;
Should validator turn out to be null, then debug a little to find the actual type used at runtime.