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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using System.Data.SqlClient;

namespace BTG_Database
{
    public partial class frmAnmeldung : Form
    {
        public frmAnmeldung()
        {
            InitializeComponent();
        }

        private void btnAnmelden_Click(object sender, EventArgs e)
        {
            try
            {
                SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Data.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");
                SqlDataAdapter sda = new SqlDataAdapter("Select Count(*) From Login where Username='" + txtUsername.Text + "' and Password = '" + txtPasswort.Text + "'", con);

                DataTable dt = new DataTable();
                sda.Fill(dt);

                if (dt.Rows.Count == 1 && dt.Rows[0][0].ToString() == "1")
                {
                    frmBTGDatabase.label_1.Text = "Angemeldet";
                    frmBTGDatabase.button_1.Enabled = true;
                    frmBTGDatabase.button_2.Enabled = true;
                    frmBTGDatabase.button_3.Enabled = true;
                    frmBTGDatabase.button_4.Enabled = true;
                    frmBTGDatabase.button_5.Enabled = true;
                    frmBTGDatabase.button_6.Enabled = true;
                    this.Close();
                }
                else
                {
                    if (dt.Rows.Count == 2 && dt.Rows[1][1].ToString() == "1")
                //  if (txtUsername.Text == "Admin" && txtPasswort.Text == "111111")
                    {
                    frmBTGDatabase.label_1.Text = "Angemeldet";
                    frmBTGDatabase.button_1.Enabled = true;
                    frmBTGDatabase.button_2.Enabled = true;
                    frmBTGDatabase.button_3.Enabled = true;
                    frmBTGDatabase.button_4.Enabled = true;
                    frmBTGDatabase.button_5.Enabled = true;
                    this.Close();

                    }
                    else
                    {
                        MessageBox.Show("Benutzername oder Passwort falsch!");
                    }
                }
                       
            }
            catch
            {
                MessageBox.Show("Probleme bei der Datenbankanbindung Data.mdf ");
            }
        }

        private void frmAnmeldung_Load(object sender, EventArgs e)
        {
            this.ActiveControl = txtUsername;
            frmBTGDatabase.toolstripmenuitem_1.Enabled = false;
        }

        private void frmAnmeldung_Closed(object sender, FormClosedEventArgs e)
        {
            frmBTGDatabase.toolstripmenuitem_1.Enabled = true;
        }

        private void btnSchließen_Click(object sender, EventArgs e)
        {
            this.Close();
        }
    }
}                    

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        private void btnAnmelden_Click(object sender, EventArgs e)
        {
            try
            {
                SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Data.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");
                SqlCommand cmd = new SqlCommand("Select * From Login where Username='" + txtUsername.Text + "' and Password = '" + txtPasswort.Text + "'", con);
                con.Open();

                SqlDataReader re = cmd.ExecuteReader();

                if (re.Read())
                {
                    frmBTGDatabase.label_1.Text = "Angemeldet";
                    frmBTGDatabase.button_1.Enabled = true;
                    frmBTGDatabase.button_2.Enabled = true;
                    frmBTGDatabase.button_3.Enabled = true;
                    frmBTGDatabase.button_4.Enabled = true;
                    frmBTGDatabase.button_5.Enabled = true;
                    frmBTGDatabase.button_6.Enabled = true;
                    this.Close();
                }
                else
                {
                    MessageBox.Show("Benutzername oder Passwort falsch!");
                    this.Close();                                      
                }
                       
            }
            catch
            {
                MessageBox.Show("Probleme bei der Datenbankanbindung Data.mdf ");
            }
        }                    

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namespace BTG_Database
{
    public partial class frmBenutzerkonto : Form
    {
        private string message = "Möchten Sie wirklich das Fenster BTG-Benutzerkonto verlassen?";
        private string caption = "Fenster verlassen";

        public frmBenutzerkonto()
        {
            InitializeComponent();
        }

        private void lOGINBindingNavigatorSaveItem_Click(object sender, EventArgs e)
        {
            this.Validate();
            this.lOGINBindingSource.EndEdit();
            this.tableAdapterManager.UpdateAll(this.dataDataSet1);

        }

        private void frmBenutzerkonto_Load(object sender, EventArgs e)
        {
            this.lOGINTableAdapter.Fill(this.dataDataSet1.LOGIN);
            this.lOGINTableAdapter.Fill(this.dataDataSet1.LOGIN);
            frmBTGDatabase.button_6.Enabled = false;

        }

        private void lOGINDataGridView_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }

        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            this.Close(); 
        }

        private void frmBenutzerkonto_Closed(object sender, FormClosedEventArgs e)
        {
            frmBTGDatabase.button_6.Enabled = true;
        }

        private void frmBenutzerkonto_Closing(object sender, FormClosingEventArgs e)
        {
            DialogResult result = MessageBox.Show(message, caption, MessageBoxButtons.YesNo, MessageBoxIcon.Question);

            if (result == DialogResult.No)
            {
                e.Cancel = true;
            }
        }
    }
}                    

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        private void frmBenutzerkonto_Load(object sender, EventArgs e)
        {
            this.lOGINTableAdapter.Fill(this.dataDataSet1.LOGIN);
            this.lOGINTableAdapter.Fill(this.dataDataSet1.LOGIN);
            frmBTGDatabase.button_6.Enabled = false;
        }                    

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SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\UserData.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");                    

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SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\User\Documents\Verwalten.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");                    

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SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Verwalten.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");                    

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SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Program Files\Microsoft SQL Server\MSSQL12.SQLEXPRESS\MSSQL\DATA\Test.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");                    

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SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Test.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");                    

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SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Test.mdf;Integrated Security=True;Connect Timeout=30");                    

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Server=myServerAddress;Database=myDataBase;Trusted_Connection=True;                    

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AccessControl.IsAdmin = Convert.ToBoolean(reader["Administrator"]);                    

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        private static string GetConnectionString()
        {
            return "Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\\UserData.mdf;Integrated Security=True;Connect Timeout=30; MultipleActiveResultSets=True";
        }


        public bool Access(string username, string password)
        {
            SqlDataReader re_access = null;
            StringBuilder errorMessages = new StringBuilder();
           
            using (SqlConnection con = new SqlConnection(@GetConnectionString()))
            {
                try
                {
                    SqlCommand cmd = new SqlCommand("Select * From Usertable where Username='" + username + "' and Password = '" + password + "'", con);
                    SqlCommand cmd_access = new SqlCommand("Select * From Usertable where Username='" + username + "' and Password = '" + password + "' and Access='" + "Admin" + "'", con);

                    con.Open();

                    using (SqlDataReader re = cmd.ExecuteReader())
                    {
                        while (re.Read())
                        {
                            access = true;

                            re_access = cmd_access.ExecuteReader();
                            using (re_access)
                            {
                                while (re_access.Read())
                                {
                                    isAdmin = "Admin";
                                }
                            }
                        }
                    }

                    con.Close();
                }
                catch (SqlException ex)
                {
                    for (int i = 0; i < ex.Errors.Count; i++)
                    {
                        errorMessages.Append("Index #" + i + "\n" +
                            "Message: " + ex.Errors[i].Message + "\n" +
                            "LineNumber: " + ex.Errors[i].LineNumber + "\n" +
                            "Source: " + ex.Errors[i].Source + "\n" +
                            "Procedure: " + ex.Errors[i].Procedure + "\n");
                    }
                    access = false;
                    System.Windows.Forms.MessageBox.Show(errorMessages.ToString());
                    con.Close();
                }
            }
            return access;           
        }                    

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private void btnAnmelden_Click(object sender, EventArgs e)
        {

            AccessControl access = new AccessControl();

                if (access.Access(txtUsername.Text, txtPasswort.Text) && AccessControl.IsAdmin == "Admin")
                {
                    frmBTGDatabase.label_1.Text = "Angemeldet Admin";
                    frmBTGDatabase.button_1.Enabled = true;
                    frmBTGDatabase.button_2.Enabled = true;
                    frmBTGDatabase.button_3.Enabled = true;
                    frmBTGDatabase.button_4.Enabled = true;
                    frmBTGDatabase.button_5.Enabled = true;
                    frmBTGDatabase.button_6.Enabled = true;
                    this.Close();
                }
                else if (access.Access(txtUsername.Text, txtPasswort.Text))
                {
                    frmBTGDatabase.label_1.Text = "Angemeldet User";
                    frmBTGDatabase.button_1.Enabled = true;
                    frmBTGDatabase.button_2.Enabled = true;
                    frmBTGDatabase.button_3.Enabled = true;
                    frmBTGDatabase.button_4.Enabled = true;
                    frmBTGDatabase.button_5.Enabled = true;
                    this.Close();
                }
                else
                {
                    MessageBox.Show("Benutzername oder Passwort falsch!");
                    this.Close();
                }
        }                    

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[Flags]
public enum Access
{
    None = 0x0,
    Login = 0x1,
    Admin = 0xFF
}

public static Access? GetAccess(string username, string password)
{
    using (var con = new SqlConnection(GetConnectionString()))
    {
        con.Open();
        using (var cmd = con.CreateCommand())
        {
            cmd.CommandText = @"Select Access From Usertable where Username=@username and Password=@password";
            cmd.Parameters.AddWithValue("@username", username);
            cmd.Parameters.AddWithValue("@password", password);

            int? result = cmd.ExecuteScalar() as int?;

            if (!result.HasValue)
                return null; // login failed no access

            return (Access)result.Value;
        }
    }
}

// Aufruf
var access = AccessControl.GetAccess(txtUsername.Text, txtPasswort.Text);

if (access.HasValue)
{
    if (access.Value.HasFlag(Access.Admin))
    {
        // admin
    }
    else
    {
        // anderer Zugang
    }
}
else
{
    // kein Zugang 
}                    

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AccessControl.IsAdmin = Convert.ToBoolean(reader["Administrator"]);                    

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namespace BTG_Database
{
    class AccessControl
    {
        private static bool access = false;
        private static string isAdmin = "";

        private bool error = false;
        private string errormessage = "";
        
        public static bool AccessSuccessfull
        {
            get { return access; }
        }

        public static string AccessIsAdmin
        {
            get { return isAdmin; }
        }

        public bool AccesError
        {
            get { return error; }
        }

        public string AccessErrorMessage
        {
            get { return errormessage; }
        }

        private static string GetConnectionString()
        {
            return "Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\\UserData.mdf;Integrated Security=True;Connect Timeout=30";
        }

        public bool Access(string username, string password)
        {
            
          StringBuilder errorMessages = new StringBuilder();
          using(SqlConnection con = new SqlConnection(@GetConnectionString()))
          {
            try
            {                    
                    SqlCommand cmd = new SqlCommand("Select * From Usertable where Username='" + username + "' and Password = '" + password + "'", con);
                    con.Open();

                    SqlDataReader re = cmd.ExecuteReader();
                
                if (re.Read())
                    {
                        
                        access = true;
                        isAdmin = Convert.ToString(re["Access"]);
                    }
                    else
                    {
                        access = false;
                    }

                    con.Close();

             }
            catch (SqlException ex)
             {
               error = true;
               access = false;
               con.Close();
   
               for (int i = 0; i < ex.Errors.Count; i++)
               {
                   errorMessages.Append("Index #" + i + "\n" +
                       "Message: " + ex.Errors[i].Message + "\n" +
                       "LineNumber: " + ex.Errors[i].LineNumber + "\n" +
                       "Source: " + ex.Errors[i].Source + "\n" +
                       "Procedure: " + ex.Errors[i].Procedure + "\n");
               }               
               errormessage = errorMessages.ToString();              
            }
          }
                    return access;           
        }

        public void Logout()
        {
            isAdmin = "";
            access = false;
        }
    }
}