MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.IO;
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 System.Windows.Threading;
using System.Threading;
using MaterialDesignThemes.Wpf;
using NAudio.Wave;



namespace SpecWpfMash
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow
    {
        public static Snackbar Snackbar;
        public MainWindow()
        {
            InitializeComponent();

            Task.Factory.StartNew(() =>
            {
                Thread.Sleep(2500);
            }).ContinueWith(t =>
            {
                //note you can use the message queue from any thread, but just for the demo here we 
                //need to get the message queue from the snackbar, so need to be on the dispatcher
                MainSnackbar.MessageQueue.Enqueue("Welcome to SpecWpfMash");
                
            }, TaskScheduler.FromCurrentSynchronizationContext());

           // DataContext = new MainWindowViewModel(MainSnackbar.MessageQueue);

            Snackbar = this.MainSnackbar;
        }

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

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

        private void ListViewMenu_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            UserControl usc = null;
            GridMain.Children.Clear();

            switch (((ListViewItem)((ListView)sender).SelectedItem).Name)
            {
                case "ItemHome":
                    break;
                case "ItemSpec":
                    usc = new Spec();
                    GridMain.Children.Add(usc);
                    break;
                case "ItemTable":
                    usc = new Table();
                    GridMain.Children.Add(usc);
                    break;
                case "ItemSettings":
                    usc = new Settings();
                    GridMain.Children.Add(usc);
                    break;
                default:
                    break;
            }
        }

    }
}