MainWindow.xaml.cs

using Microsoft.UI;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Microsoft.UI.Xaml.Controls.Primitives;
using Microsoft.UI.Xaml.Data;
using Microsoft.UI.Xaml.Input;
using Microsoft.UI.Xaml.Media;
using Microsoft.UI.Xaml.Media.Animation;
using Microsoft.UI.Xaml.Navigation;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI;
using Windows.UI.ApplicationSettings;
using YoutubeDownloader.Pages;


namespace YoutubeDownloader
{
    /// <summary>
    /// An empty window that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainWindow : Window
    {
        public MainWindow()
        {
            this.InitializeComponent();
            AppWindow.Resize(new Windows.Graphics.SizeInt32(900, 850));
            AppWindow.SetIcon("/Assets/logo_transparent.ico");
            AppWindow.Title = "YT Downloader";            
            AppWindow.TitleBar.ExtendsContentIntoTitleBar = true;
            AppWindow.TitleBar.ButtonBackgroundColor = Colors.Transparent;
            AppWindow.TitleBar.ButtonInactiveBackgroundColor = Colors.Transparent;
        }

        private void NaviView_SelectionChanged(NavigationView sender, NavigationViewSelectionChangedEventArgs args)
        {
            if (args.IsSettingsSelected)
            {
                NavView_Navigate(typeof(SettingsPage), args.RecommendedNavigationTransitionInfo);
            }
            else if (args.SelectedItemContainer != null)
            {
                string pageName = args.SelectedItemContainer.Tag.ToString();
                Type navPageType = Type.GetType(pageName);
                NavView_Navigate(navPageType, args.RecommendedNavigationTransitionInfo);
            }
        }

        private void NavView_Navigate(Type navPageType, NavigationTransitionInfo transitionInfo)
        {
            // Get the page type before navigation so you can prevent duplicate
            // entries in the backstack.
            Type preNavPageType = ContentFrame.CurrentSourcePageType;

            // Only navigate if the selected page isn't currently loaded.
            if (navPageType is not null && !Type.Equals(preNavPageType, navPageType))
            {
                ContentFrame.Navigate(navPageType, null, transitionInfo);
            }
        }
    }
}