What if you want to add additional parameter or field in the user identity table i.e. AspNetUser. We might need this one so lets look how we can achieve it.

• Open Models/ApplicationUser.cs and add the following line of code. We can add much more field so for now only a field is added as ContactName

public class ApplicationUser : IdentityUser
{
   public string ContactName { get; set; }
}

• Once we have added the code we need to carry out a migration and then update the database as:

dotnet ef migrations add ContactNameField
dotnet ef database update

Once done our database is updated with the new field added as ContactName

• Now open up Models/AccountViewModels/RegisterViewModel.cs and add the following code

[Required]
[Display(Name = "Name")]
public string ContactName { get; set; }

• Then reach out to Views/Account/Register.chstml and add up the following code

<div class="form-group">
     <label asp-for="ContactName"></label>
     <input asp-for="ContactName" class="form-control" />
     <span asp-validation-for="ContactName" class="text-danger"></span>
</div>

• Open up Controllers/AccountController then add the following code

var user = new ApplicationUser { ContactName=model.ContactName, UserName = model.Email, Email = model.Email };

Once Completed Do The Same For:

• View/Manage/Index.cshtml,
• Models/ManageViewModels/IndexViewModel.cs and in
• Index method in ManageControler class.

Now, we need to add the new data to claim for this create a new class with the code below

public class MyUserClaimsPrincipalFactory : UserClaimsPrincipalFactory<ApplicationUser, IdentityRole>
    {
        public MyUserClaimsPrincipalFactory(
            UserManager<ApplicationUser> userManager,
            RoleManager<IdentityRole> roleManager,
            IOptions<IdentityOptions> optionsAccessor)
            : base(userManager, roleManager, optionsAccessor) {
        }

        protected override async Task<ClaimsIdentity> GenerateClaimsAsync(ApplicationUser user) {
            var identity = await base.GenerateClaimsAsync(user);
            identity.AddClaim(new Claim("ContactName", user.ContactName ?? ""));
            return identity;
        }
    }

Now we need to register it in DI container in ConfigureServices  methods of the Startup class as

public void ConfigureServices(IServiceCollection services) {
   .
   .
    services.AddIdentity<ApplicationUser, IdentityRole>()
        .AddEntityFrameworkStores<ApplicationDbContext>()
        .AddDefaultTokenProviders();
     
    //add the following line of code
    services.AddScoped<IUserClaimsPrincipalFactory<ApplicationUser>, MyUserClaimsPrincipalFactory>();
    .
    .
}

So, this is all about the setup. Now for accessing the data in view it can be done by a single line of code as:

@(User.FindFirst("ContactName").Value)

Ref: korzh.com