MyAvaloniaDemo/AuroraDesk.Presentation/Views/Pages/FileExplorerPageView.axaml

<reactive:ReactiveUserControl xmlns="https://github.com/avaloniaui"
                              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                              xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
                              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
                              xmlns:vm="using:AuroraDesk.Presentation.ViewModels.Pages"
                              xmlns:avaloniaEdit="clr-namespace:AvaloniaEdit;assembly=AvaloniaEdit"
                              xmlns:attached="using:AuroraDesk.Presentation.Attached"
                              xmlns:reactive="using:ReactiveUI.Avalonia"
                              mc:Ignorable="d"
                              d:DesignWidth="1200"
                              d:DesignHeight="800"
                              x:Class="AuroraDesk.Presentation.Views.Pages.FileExplorerPageView"
                              x:DataType="vm:FileExplorerPageViewModel">

    <Design.DataContext>
        <vm:FileExplorerPageViewModel />
    </Design.DataContext>

    <Grid RowDefinitions="Auto,*">
        <!-- 顶部目录选择区 -->
        <Border Grid.Row="0"
                Background="{StaticResource BackgroundLight}"
                BorderBrush="{StaticResource BorderLight}"
                BorderThickness="0,0,0,1"
                Padding="20">
            <Grid ColumnDefinitions="*,Auto,Auto" ColumnSpacing="16">
                <StackPanel Grid.Column="0" Spacing="10">
                    <TextBlock Text="文件目录浏览"
                               FontSize="24"
                               FontWeight="Bold"
                               Foreground="{StaticResource TextPrimary}"/>
                    <TextBlock Text="选择一个目录，左侧显示文件列表，右侧使用 AvaloniaEdit 预览文件内容"
                               FontSize="14"
                               Foreground="{StaticResource SecondaryGrayDark}"/>
                    <TextBlock Text="{Binding StatusMessage}"
                               FontSize="13"
                               Foreground="{StaticResource TextSecondary}"/>
                </StackPanel>
                
                <StackPanel Grid.Column="1"
                            Orientation="Horizontal"
                            Spacing="10"
                            VerticalAlignment="Center">
                    <TextBox Width="360"
                             Text="{Binding SelectedDirectory}"
                             IsReadOnly="True"
                             Watermark="请选择目录"
                             HorizontalAlignment="Stretch"/>
                </StackPanel>
                
                <StackPanel Grid.Column="2"
                            Orientation="Horizontal"
                            Spacing="10"
                            VerticalAlignment="Center">
                    <Button Content="选择目录"
                            Command="{Binding BrowseDirectoryCommand}"
                            HorizontalAlignment="Right"/>
                    <Button Content="刷新列表"
                            Command="{Binding RefreshDirectoryCommand}"
                            HorizontalAlignment="Right"/>
                </StackPanel>
            </Grid>
        </Border>

        <!-- 下方左右布局 -->
        <Grid Grid.Row="1" ColumnDefinitions="320,*" ColumnSpacing="12" Margin="12">
            <!-- 左侧：文件树 -->
            <Border Background="{StaticResource BackgroundWhite}"
                    BorderBrush="{StaticResource BorderLight}"
                    BorderThickness="1"
                    CornerRadius="10"
                    Padding="16">
                <Grid RowDefinitions="Auto,Auto,Auto,*" RowSpacing="12">
                    <StackPanel Grid.Row="0" Orientation="Horizontal" VerticalAlignment="Center" Spacing="8">
                        <TextBlock Text="文件树"
                                   FontSize="18"
                                   FontWeight="SemiBold"
                                   Foreground="{StaticResource TextPrimary}"/>
                        <Border Background="{StaticResource BackgroundLight}"
                                CornerRadius="12"
                                Padding="10,4">
                            <TextBlock Text="{Binding TotalFileCount, StringFormat='文件数：{0}'}"
                                       FontSize="12"
                                       Foreground="{StaticResource TextSecondary}"/>
                        </Border>
                    </StackPanel>

                    <TextBlock Grid.Row="1"
                               Text="展开左侧树并点击文件，即可在右侧预览内容"
                               FontSize="13"
                               Foreground="{StaticResource SecondaryGrayDark}"/>

                    <TextBox Grid.Row="2"
                             Height="36"
                             CornerRadius="8"
                             Text="{Binding SearchQuery, UpdateSourceTrigger=PropertyChanged}"
                             Watermark="搜索文件或文件夹"
                             VerticalAlignment="Center"/>

                    <TreeView Grid.Row="3"
                              ItemsSource="{Binding FilteredTreeItems}"
                              SelectedItem="{Binding SelectedNode}"
                              Background="{StaticResource BackgroundLight}"
                              BorderThickness="0"
                              ScrollViewer.HorizontalScrollBarVisibility="Disabled">
                        <TreeView.Styles>
                            <Style Selector="TreeViewItem">
                                <Setter Property="Margin" Value="0,2,0,2"/>
                                <Setter Property="Padding" Value="6,4"/>
                            </Style>
                        </TreeView.Styles>
                        <TreeView.DataTemplates>
                            <TreeDataTemplate DataType="vm:FileExplorerPageViewModel+FileTreeNode"
                                              ItemsSource="{Binding Children}">
                                <StackPanel Spacing="2">
                                    <TextBlock Text="{Binding Name}"
                                               FontWeight="SemiBold"
                                               Foreground="{StaticResource TextPrimary}"
                                               TextTrimming="CharacterEllipsis"/>
                                    <TextBlock Text="{Binding SizeDisplay}"
                                               FontSize="11"
                                               Foreground="{StaticResource SecondaryGrayDark}"/>
                                </StackPanel>
                            </TreeDataTemplate>
                        </TreeView.DataTemplates>
                    </TreeView>
                </Grid>
            </Border>

            <!-- 右侧：文件内容展示 -->
            <Border Grid.Column="1"
                    Background="{StaticResource BackgroundWhite}"
                    BorderBrush="{StaticResource BorderLight}"
                    BorderThickness="1"
                    CornerRadius="10"
                    Padding="16">
                <Grid RowDefinitions="Auto,*" RowSpacing="12">
                    <StackPanel Orientation="Vertical" Spacing="6">
                        <TextBlock Text="{Binding SelectedFileName}"
                                   FontSize="20"
                                   FontWeight="SemiBold"
                                   Foreground="{StaticResource TextPrimary}"/>
                        <TextBlock Text="{Binding SelectedFileInfo}"
                                   FontSize="13"
                                   Foreground="{StaticResource SecondaryGrayDark}"/>
                        <StackPanel Orientation="Horizontal" Spacing="8" VerticalAlignment="Center">
                            <TextBlock Text="语法高亮："
                                       FontSize="13"
                                       Foreground="{StaticResource SecondaryGrayDark}"
                                       VerticalAlignment="Center"/>
                            <ComboBox ItemsSource="{Binding AvailableHighlightLanguages}"
                                      SelectedItem="{Binding SelectedHighlightLanguage}"
                                      MinWidth="150"
                                      MaxWidth="200"
                                      HorizontalAlignment="Left"/>
                        </StackPanel>
                    </StackPanel>

                    <Border Grid.Row="1"
                            Background="{StaticResource BackgroundLight}"
                            BorderBrush="{StaticResource BorderLight}"
                            BorderThickness="1"
                            CornerRadius="8"
                            Padding="0">
                        <avaloniaEdit:TextEditor attached:TextEditorAssist.Document="{Binding Document}"
                                                 IsReadOnly="True"
                                                 ShowLineNumbers="True"
                                                 FontFamily="Consolas, 'Courier New', monospace"
                                                 FontSize="14"
                                                 HorizontalScrollBarVisibility="Auto"
                                                 VerticalScrollBarVisibility="Visible"
                                                 Background="{StaticResource BackgroundWhite}"
                                                 Foreground="{StaticResource TextPrimary}"
                                                 attached:TextMateHelper.Language="{Binding ActiveHighlightLanguage}"
                                                 Margin="0"/>
                    </Border>
                </Grid>
            </Border>
        </Grid>
    </Grid>
</reactive:ReactiveUserControl>