ASP.NET MVC Login by email instead of username

To answer:

Is there any ways to compare the inputted email with the Email column instead of Username?

This is probably not the best answer but the SignInManager should have access to UserManager which has a Users property. So you could lookup the user based on the email and then using the result call the signin method.

Something like this (untested):

var user = SignInManager.UserManage.Users.Where(u => u.email == model.Email).FirstOrDefault();
var result = await SignInManager.PasswordSignInAsync(user.UserName, model.Password, model.RememberMe, shouldLockout: false);

You would want to check that the user was populated otherwise return invalid login details error. Same as if PasswordSignInAsync failed.

Here is what to do as @ChrisMoutray suggested, find the username for the email provided and log in. I put it here.

Instantiate usermanager and signinmanager

private readonly SignInManager<ApplicationUser> signInManager;
private readonly UserManager<ApplicationUser> userManager;

        public AccountController(SignInManager<ApplicationUser> signInManager, UserManager<ApplicationUser> userManager)
        {
            this.signInManager = signInManager;
            this.userManager = userManager;
        }

and then in the Login (post) task:

  var user = await userManager.FindByEmailAsync(model.Email);
  var result = await signInManager.PasswordSignInAsync(user.UserName, model.Password, model.RememberMe, lockoutOnFailure: false);

PS. Found myself in this old post so just adding a working solution.

The reason is because when you register. you get username = email.

  public async Task<ActionResult> Register(RegisterViewModel model)
    {
        if (ModelState.IsValid)
        {
            var user = new ApplicationUser { UserName = model.Email, Email = model.Email };
            var result = await UserManager.CreateAsync(user, model.Password);