如果我理解正确的话：在我们检查帐户是否处于活动状态之前，您要确保用户名和密码都正确吗？

protected void LogIn(object sender, EventArgs e)
{
    var manager = Context.GetOwinContext().GetUserManager<ApplicationUserManager>();
    var signinManager = Context.GetOwinContext().GetUserManager<ApplicationSignInManager>();
    var user = manager.FindByName(username.Text);

    if (IsValid)
    {
        if (user != null)
        {
            var result = signinManager.PasswordSignIn(username.Text, Password.Text, RememberMe.Checked, shouldLockout: true);

            // If username and password is correct check if account is activated.
            if(!user.EmailConfirmed && result == SignInStatus.Success)
            {
                FailureText.Text = "Invalid login attempt. You must have a confirmed email account.";
                ErrorMessage.Visible = true;
                return;
            }        

            switch (result)
            {
                case SignInStatus.Success:
                    IdentityHelper.RedirectToReturnUrl(Request.QueryString["ReturnUrl"], 
                                                           Response);
                    break;
                case SignInStatus.LockedOut:
                    //Response.Redirect("/Account/Lockout");    
                    FailureText.Text = "This account has been locked out, please try again later.";
                    ErrorMessage.Visible = true;
                    return;

                case SignInStatus.RequiresVerification:
                    Response.Redirect(String.Format("/Account/TwoFactorAuthenticationSignIn?ReturnUrl={0}&RememberMe={1}",
                                                    Request.QueryString["ReturnUrl"],
                                                    RememberMe.Checked),
                                                    true);
                    break;
                case SignInStatus.Failure:
                default:
                    FailureText.Text = "Invalid login attempt";
                    ErrorMessage.Visible = true;
                    break;    
            }                
        }    
        else
        {
            FailureText.Text = "Account not found.";
            ErrorMessage.Visible = true;
        }
    }
}

要检查用户是否已确认，需要做一些小的修改，您需要检查IsEmailConfirmed属性，以查看用户是否已确认帐户。
This article很好地解释了流程以及如何执行这些操作。下面的代码片段摘自那篇文章。

var user = manager.FindByName(Email.Text);
    if (user != null)
    {
        if (!user.EmailConfirmed)
        {
            FailureText.Text = "Invalid login attempt. You must have a confirmed email address. Enter your email and password, then press 'Resend Confirmation'.";
            ErrorMessage.Visible = true;
            ResendConfirm.Visible = true;
        }
        else
        {
             // your other logic goes here if the user is confirmed.
             ....
        }
    }
    else 
    {
        // user does not exist.
    }

在.NET 7中登录. cshtml.cs

if (result.IsLockedOut)
            {
                _logger.LogWarning("User account locked out.");
                return RedirectToPage("./Lockout");
            }
            if (result.IsNotAllowed)
            {
                var user = _signInManager.UserManager.FindByEmailAsync(Input.Email);
                if (user != null)
                {
                    if (!user.Result.EmailConfirmed)
                    {
                        ModelState.AddModelError(string.Empty, "Account isn't active, Get Your Email & click on Active link, ");
                    }
                }
                else
                {
                    ModelState.AddModelError(string.Empty, "incorrect username or password");//Email not found
                }
            }
            else
            {
                ModelState.AddModelError(string.Empty, "incorrect username or password");
                return Page();
            }