private async void loginBtn_Click(object sender, RoutedEventArgs e)
{
LoginBinder loginBinder = new LoginBinder()
{
Username = usernameTextBox.Text,
Password = passwordTextBox.Password,
};
string[] errors = userManager.Login(loginBinder);
if (errors.Length == 0)
{
//Login successful
}
else
{
//Login Failed
}
}