Question

How can you modify the standard ASP.NET MVC login pages to allow the user to login with either an email address OR their username?

Answer 1

+1 to Sparkle as that looks like it would work but I found an easier way.

In AccountModel.cs change Display attribute (just label of textbox on login page)

public class LogOnModel
{
    [Required]
    [Display(Name = "User name or Email Address")]
    public string UserName { get; set; }
    ...

In AccountController.cs change LogOn method to see if username looks like an email address, if so then try and find userName from email address.

[HttpPost]
public ActionResult LogOn(LogOnModel model, string returnUrl)
{
    if (ModelState.IsValid)
    {
        // Can login by username or email address                
        MembershipUser user = null;
        string userName;

        if (model.UserName.Contains("@"))
        {
            // Could change model.userName from email to username but this will change form values
            // if login fails (wrong pwd) which will be confusing to users, so keep in sep username string
            userName = Membership.GetUserNameByEmail(model.UserName);
            if (!String.IsNullOrEmpty(userName))
            {
                user = Membership.GetUser(userName);
            }
        }
        else
        {
            user = Membership.GetUser(model.UserName);
            userName = model.UserName;
        }

        if (user != null && validateAndLogOnUser(userName, model.Password, model.RememberMe))
        {
            // Rest of standard login code here