/ViewModel/FailedLoginCountViewModel.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using Login.Database;
using Login.Foundation;
using Login.Helpers;

namespace Login.ViewModel
{
    [Export]
    class FailedLoginCountViewModel : ValidationRuleBase, IValidationRule
    {
        private UserInformation userInformation_;
        private IDatabase dataBase_;

        [ImportingConstructor]
        public FailedLoginCountViewModel ( UserInformation userInformation, IDatabase dataBase )
        {
            userInformation_ = userInformation;
            dataBase_ = dataBase;
        }

        public bool validate ( )
        {
            int numberOfFailedLogin = dataBase_.GetNumberOfLoginTries(userInformation_.UserName);

            if ( numberOfFailedLogin <= 5 && numberOfFailedLogin >= 0)
            {
                MessageBox.Show("Number Of failed login is still ok");
                return true;
            }
            else
            {
                MessageBox.Show("Number of failed login has been exceeded");
                return false;
            }
        }

        public ERuleType RuleType
        {
            get { return ERuleType.NonInteractive; }
        }
    }
}