WIn_RustTools/RustTools/Editor/EditorWin.xaml

<?xml version="1.0" encoding="utf-8" ?>
<windowex:WindowEx
    x:Class="RustTools.Editor.EditorWin"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controlpages="using:RustTools.Editor"
    xmlns:controls="using:CommunityToolkit.WinUI.Controls"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="using:RustTools"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:windowex="using:WinUIEx"
    MinWidth="500"
    MinHeight="500"
    mc:Ignorable="d">

    <Page Name="page">
        <Page.Resources>
            <DataTemplate x:Key="FolderTemplate">
                <TreeViewItem
                    AutomationProperties.Name="{Binding Name}"
                    IsExpanded="False"
                    ItemsSource="{Binding Children}">
                    <StackPanel Orientation="Horizontal">
                        <FontIcon Glyph="&#xE8B7;" />
                        <TextBlock Margin="0,0,10,0" />
                        <TextBlock Text="{Binding Name}" />
                    </StackPanel>
                </TreeViewItem>
            </DataTemplate>

            <DataTemplate x:Key="FileTemplate">
                <TreeViewItem AutomationProperties.Name="{Binding Name}" IsExpanded="False">
                    <StackPanel Orientation="Horizontal">
                        <FontIcon Glyph="&#xE8A5;" />
                        <TextBlock Margin="0,0,10,0" />
                        <TextBlock Text="{Binding Name}" />
                    </StackPanel>
                </TreeViewItem>
            </DataTemplate>
            <controlpages:ExplorerItemTemplateSelector
                x:Key="ExplorerItemTemplateSelector"
                FileTemplate="{StaticResource FileTemplate}"
                FolderTemplate="{StaticResource FolderTemplate}" />

        </Page.Resources>

        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto" />
                <ColumnDefinition Width="Auto" />
                <ColumnDefinition Width="*" />
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>
            <Grid
                Grid.Row="0"
                Padding="9"
                Visibility="Visible">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition />
                    <ColumnDefinition Width="Auto" />
                </Grid.ColumnDefinitions>
                <TextBlock
                    Name="TitleText"
                    Grid.Column="0"
                    Margin="16,0,0,0" />
            </Grid>
            <ScrollViewer
                x:Name="scrollview"
                Grid.Row="2"
                Grid.Column="0"
                Width="300"
                Margin="0,9,0,6"
                Padding="0,0,16,0"
                HorizontalScrollBarVisibility="Auto"
                VerticalScrollBarVisibility="Auto">

                <controlpages:EditorTreeView
                    Name="treeView"
                    DoubleTapped="treeView_DoubleTapped"
                    ItemInvoked="TreeView_ItemInvoked"
                    ItemTemplateSelector="{StaticResource ExplorerItemTemplateSelector}"
                    ItemsSource="{x:Bind DataSource}"
                    ScrollViewer.IsVerticalRailEnabled="False"
                    SelectionMode="Single" />
            </ScrollViewer>

            <controls:PropertySizer
                Grid.Row="1"
                Grid.Column="1"
                Binding="{x:Bind scrollview.Width, Mode=TwoWay}"
                Maximum="350"
                Minimum="200"
                Visibility="Visible" />
            <Grid
                x:Name="gridedit"
                Grid.Row="1"
                Grid.Column="2">
                <Grid.RowDefinitions>
                    <RowDefinition Height="*" />
                </Grid.RowDefinitions>
                <TabView
                    x:Name="tabview"
                    Grid.Row="0"
                    Height="auto"
                    IsAddTabButtonVisible="False"
                    TabCloseRequested="TabView_TabCloseRequested"
                    TabItemsSource="{x:Bind TabViewList}" />

            </Grid>
        </Grid>
    </Page>
</windowex:WindowEx>