[RESOLVED] login check user and password

[opticaltim]

Hi, i'm currently stuck on a login application. When I hit the login button I want to check if the user is in my sql database and if the password is correct. For some reason every login is correct.

LoginWindow

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.Data.SqlClient;
using Monopoly.Connector;
using Monopoly.Library;

namespace Monopoly.UI
{
    /// <summary>
    /// Interaction logic for LoginWindow.xaml
    /// </summary>
    public partial class LoginWindow : Window
    {
        Gateway connector = Gateway.Instance;

        public LoginWindow()
        {
            InitializeComponent();
        }

        private void btnLogin_Click(object sender, RoutedEventArgs e)
        {
            if (ValidateLogin())
            {
                try
                {
                    Player validPlayer = connector.Proxy.VerifyUserInput(txtUserName.Text, txtPaswoord.Password);
                    if (validPlayer != null)
                    {


                        Start(validPlayer);
                    }
                    else
                    {
                        MessageBox.Show("Incorrect user or password");
                    }

                }
                catch (Exception ex)
                {
                    MessageBox.Show("Oops, something went wrong: " + ex.Message);
                }
                
            }         
        }

        private void Start(Player p)
        {
            MainWindow m = new MainWindow(p);
            m.Show();
            this.Close();
        }

        private bool ValidateLogin()
        {
            bool isLoginValid = true;
            StringBuilder messageBuilder = new StringBuilder(2);

            if (string.IsNullOrEmpty(txtUserName.Text))
            {
                isLoginValid = false;
                messageBuilder.AppendLine("Username is required.");
            }
            if (string.IsNullOrEmpty(txtPaswoord.Password))
            {
                isLoginValid = false;
                messageBuilder.AppendLine("Password is required.");
            }
            if (!isLoginValid)
            {
               MessageBox.Show(messageBuilder.ToString(), "Please fill in the required fields", MessageBoxButton.OK, MessageBoxImage.Information );
            }
            return isLoginValid;
        }

        private void btnRegister_Click(object sender, RoutedEventArgs e)
        {

        }
    }
}

Database

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;

namespace Monopoly.Data
{
    public class Database
    {
        private static String ConnectionString
        {
            get
            {
                return @"Data Source=PC-TIM; Initial Catalog=Monopoly; Integrated Security=True";
               
            }
        }

        // Connectie maken en openen
        private static SqlConnection GetConnection()
        {
            try
            {
                SqlConnection oCon = new SqlConnection(ConnectionString);
                oCon.Open();
                return oCon;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return null;
            }
            


        }

        // De connectie sluiten en vrijgeven
        private static void ReleaseConnection(SqlConnection oCon)
        {
            if (oCon != null)
            {
                oCon.Close();
                oCon.Dispose();
            }
        }


        private static SqlCommand BuildCommandParameters(String sStoredProcedureNaam, params SqlParameter[] dbParams)
        {
            SqlConnection oCon = GetConnection();
            SqlCommand oCommand = oCon.CreateCommand();
            oCommand.CommandType = CommandType.StoredProcedure;
            oCommand.CommandText = sStoredProcedureNaam;

            if (dbParams != null)
            {
                foreach (SqlParameter oPar in dbParams)
                {
                    oCommand.Parameters.Add(oPar);
                }
            }
            return oCommand;
        }


        // Een DataTable ophalen
        public static DataTable GetDT(String sStoredProcedureNaam, params SqlParameter[] dbParams)
        {
            SqlCommand oCommand = null;
            try
            {

                oCommand = BuildCommandParameters(sStoredProcedureNaam, dbParams);

                SqlDataAdapter oDA = new SqlDataAdapter();
                oDA.SelectCommand = oCommand;

                DataTable oDT = new DataTable();
                oDA.Fill(oDT);

                return oDT;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return null;
            }

            finally
            {
                if (oCommand != null)
                {
                    ReleaseConnection(oCommand.Connection);
                }
            }
        }



        // DataReader ophalen
        public static SqlDataReader GetDR(String sStoredProcedureNaam, params SqlParameter[] dbParams)
        {
            SqlCommand oCommand = null;
            SqlDataReader oDR = null;

            try
            {
                oCommand = BuildCommandParameters(sStoredProcedureNaam, dbParams);
                oDR = oCommand.ExecuteReader(CommandBehavior.CloseConnection);

                return oDR;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return null;
            }

            finally
            {
                if (oCommand != null)
                {
                    ReleaseConnection(oCommand.Connection);
                }
            }
        }

        // Slechts 1 resultaat teruggeven
        public static Object ExecuteScalar(String sStoredProcedureNaam, params SqlParameter[] dbParams)
        {
            SqlCommand oCommand = null;

            try
            {
                oCommand = BuildCommandParameters(sStoredProcedureNaam, dbParams);
                Object oObject = oCommand.ExecuteScalar();

                return oObject;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return null;
            }

            finally
            {
                if (oCommand != null)
                {
                    ReleaseConnection(oCommand.Connection);
                }
            }
        }


        // SQL zonder terugkeer resultaat uitvoeren
        public static void ExcecuteSQL(String sStoredProcedureNaam, params SqlParameter[] dbParams)
        {
            SqlCommand oCommand = null;

            try
            {
                oCommand = BuildCommandParameters(sStoredProcedureNaam, dbParams);
                oCommand.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }

            finally
            {
                if (oCommand != null)
                {
                    ReleaseConnection(oCommand.Connection);
                }
            }
        }

    }
}

PlayerData

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Serialization;
using Monopoly.Library;
using System.Data;
using System.Data.SqlClient;


namespace Monopoly.Data
{
  //  [DataContract]
    public class PlayerData
    {

        public static Player VerifyUserInput(string naam, string paswoord)
        {

            //ParameterList aanmaken
            List<SqlParameter> parameters = new List<SqlParameter>();

            //Parameter(s) aanmaken
            SqlParameter parA = new SqlParameter("PlayerName", naam);
            SqlParameter parB = new SqlParameter("PlayerPaswoord", paswoord);
            //Parameter(s) toevoegen
            parameters.Add(parA);
            parameters.Add(parB);


            DataTable dt = Database.GetDT("dbo.Player", parameters.ToArray());
            SqlCommand command = new SqlCommand("SELECT * FROM [Player] WHERE [PlayerName]='" + naam + "' AND [PlayerPaswoord]='" + paswoord + "'");

            if (dt.Rows.Count == 1)
            {
                return new Player(naam, paswoord);
            }

            return null;

        }
}
}

When i try to run it I get a NUllRefexeception on:

            if (dt.Rows.Count == 1)
            {
                return new Player(naam, paswoord);
            }

Can anyone help? Thanks!