优化更新代码，添加界面功能并整合

WPFluent.Gallery/App.xaml.cs

@@ -0,0 +1,29 @@
+
+using WPFluent.Appearance;
+using WPFluent.Controls;
+
+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Data;
+using System.Linq;
+using System.Threading.Tasks;
+
+using System.Windows;
+
+
+namespace WPFluent.Gallery
+{
+    /// <summary>
+    /// App.xaml 的交互逻辑
+    /// </summary>
+    public partial class App : Application
+    {
+        public App()
+        {
+            SystemMenuThemeManager.Apply();
+            Splash.ShowAsync("pack://application:,,,/WPFluent.Gallery;component/wpfui.png", 0.98d);
+            InitializeComponent();
+        }
+    }
+}