优化

Sample/MainWindow.xaml

@@ -0,0 +1,27 @@
+<Window
+    x:Class="Sample.MainWindow"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:local="clr-namespace:Sample"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    Title="MainWindow"
+    Width="800"
+    Height="450"
+    mc:Ignorable="d">
+    <Grid Background="{DynamicResource AppBackgroundBrush}">
+        <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
+            <TextBlock
+                FontSize="24"
+                Foreground="{DynamicResource AppTextBrush}"
+                Text="背景和文字都会渐变" />
+
+            <Button
+                x:Name="SwitchThemeButton"
+                Margin="0,20,0,0"
+                Padding="15,8"
+                Click="SwitchThemeButton_Click"
+                Content="切换主题" />
+        </StackPanel>
+    </Grid>
+</Window>