C# Kleines Problem

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Threading.Tasks;
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.Navigation;
using System.Windows.Shapes;
using IniParser;
using IniParser.Model;
using MySql.Data.MySqlClient;




namespace Keybinder
{
    /// <summary>
    /// Interaktionslogik für MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            MouseDown += Window_MouseDown;
            var parser = new FileIniDataParser();


            //Setup
            if (!Directory.Exists("C:\\NNKeybinder"))
           {
                Directory.CreateDirectory("C:\\NNKeybinder");
           }
           if (!Directory.Exists("C:\\NNKeybinder\\Settings"))
           {
               Directory.CreateDirectory("C:\\NNKeybinder\\Settings");
           }
           if(!File.Exists("C:\\NNKeybinder\\Settings\\main.conf"))
           {
                File.Create("C:\\NNKeybinder\\Settings\\main.conf").Close();
                IniData mainConfigBUILDING = parser.ReadFile("C:\\NNKeybinder\\Settings\\main.conf");
                mainConfigBUILDING["USER"]["UUID"] = "UUID";
                mainConfigBUILDING["USER"]["Username"] = "Gast";
                mainConfigBUILDING["USER"]["Fraktion"] = "-";
                parser.WriteFile("C:\\NNKeybinder\\Settings\\main.conf", mainConfigBUILDING);
            }


            IniData mainConfig = parser.ReadFile("C:\\NNKeybinder\\Settings\\main.conf");
            UserNameBox.Text = mainConfig["USER"]["Username"];


            if(mainConfig["USER"]["Username"] == "Gast")
            {
                ButtonPopUpLogout.Visibility = Visibility.Collapsed;
            } else
            {
                ButtonPopUpLogin.Visibility = Visibility.Collapsed;
            }


            try
            {
                string connectionString = "SERVER=****;" +
                                      "DATABASE=****;" +
                                      "UID=****;" +
                                      "PASSWORD=****;";


                MySqlConnection connection = new MySqlConnection(connectionString);
                connection.Open();
                if(connection.State == System.Data.ConnectionState.Open)
                    System.Windows.Forms.MessageBox.Show("Connection established!", "MySQL Information",
                        System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Information);
            }
            catch (MySql.Data.MySqlClient.MySqlException ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message, "MySQL Exception",
                                System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Error);
            }
            catch (Exception ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message, "Unknown Exception",
                                System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Error);
            }


            if(mainConfig["USER"]["UUID"] == "")
            {


            }


        }


        //Logout Button
        private void ButtonPopUpLogout_Click(object sender, RoutedEventArgs e)
        {
            new LogoutQuestion().Show();
        }


        //Programmschließen Button
        private void ButtonPopUpClose_Click(object sender, RoutedEventArgs e)
        {
            Application.Current.Shutdown();
        }


        private void ButtonOpenMenu_Click(object sender, RoutedEventArgs e)
        {
            ButtonCloseMenu.Visibility = Visibility.Visible;
            ButtonOpenMenu.Visibility = Visibility.Collapsed;
        }


        private void ButtonCloseMenu_Click(object sender, RoutedEventArgs e)
        {
            ButtonOpenMenu.Visibility = Visibility.Visible;
            ButtonCloseMenu.Visibility = Visibility.Collapsed;
        }


        private void Window_MouseDown(object sender, MouseButtonEventArgs e)
        {
            if (e.ChangedButton == MouseButton.Left)
                DragMove();
        }


        public class TextBoxText
        {
            public string textdata { get; set; }
        }


        private void ButtonPopUpLogin_Click(object sender, RoutedEventArgs e)
        {


        }
    }
}