WIP: GUI

静态分析没有问题了。但是一尝试扫描文件夹就炸。怀疑是权限问题，但不确定。

src/GUI/Views/MainWindow.axaml

@@ -1,20 +1,62 @@
 <Window xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:vm="using:GUI.ViewModels"
+        xmlns:views="using:GUI.Views"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+        mc:Ignorable="d" d:DesignWidth="1200" d:DesignHeight="800"
         x:Class="GUI.Views.MainWindow"
         x:DataType="vm:MainWindowViewModel"
+        x:Name="Root"
         Icon="/Assets/avalonia-logo.ico"
-        Title="Resonance">
+        Title="Resonance"
+        Width="1200" Height="800"
+        MinWidth="900" MinHeight="600">
 
     <Design.DataContext>
-        <!-- This only sets the DataContext for the previewer in an IDE,
-             to set the actual DataContext for runtime, set the DataContext property in code (look at App.axaml.cs) -->
         <vm:MainWindowViewModel/>
     </Design.DataContext>
 
-    <TextBlock Text="{Binding Greeting}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
+    <Grid RowDefinitions="Auto,*,Auto">
 
+        <!-- 工具栏 -->
+        <Border Grid.Row="0" Padding="6,4" BorderBrush="{DynamicResource SystemBaseLowColorBrush}"
+                BorderThickness="0,0,0,1" Background="{DynamicResource SystemAltMediumColorBrush}">
+            <StackPanel Orientation="Horizontal" Spacing="4">
+                <Button Content="📁 扫描目录" x:Name="ScanButton" Height="28" Padding="8,0"/>
+                <Button Content="⚙ 偏好设置" Height="28" Padding="8,0" IsEnabled="False"/>
+            </StackPanel>
+        </Border>
+
+        <!-- 主内容区：三栏布局 -->
+        <Grid Grid.Row="1" ColumnDefinitions="220,4,*,4,300">
+
+            <!-- 左侧标签树 -->
+            <Border Grid.Column="0" BorderBrush="{DynamicResource SystemBaseLowColorBrush}"
+                    BorderThickness="0,0,1,0">
+                <views:TagTreeView DataContext="{Binding TagTreeVM}"/>
+            </Border>
+
+            <GridSplitter Grid.Column="1" Width="4" Background="Transparent"/>
+
+            <!-- 中间文件列表 -->
+            <Border Grid.Column="2">
+                <views:FileListView DataContext="{Binding FileListVM}"/>
+            </Border>
+
+            <GridSplitter Grid.Column="3" Width="4" Background="Transparent"/>
+
+            <!-- 右侧元数据面板 -->
+            <Border Grid.Column="4" BorderBrush="{DynamicResource SystemBaseLowColorBrush}"
+                    BorderThickness="1,0,0,0">
+                <views:MetadataPanelView DataContext="{Binding MetadataPanelVM}"/>
+            </Border>
+        </Grid>
+
+        <!-- 底部播放栏 -->
+        <Border Grid.Row="2">
+            <views:PlayerBarView DataContext="{Binding PlayerBarVM}"/>
+        </Border>
+
+    </Grid>
 </Window>