如何从treeview WPF中选择和读取txt文件

<TreeView x:Name="treeView" ItemsSource="{Binding}">
    <TreeView.ItemTemplate>
        <HierarchicalDataTemplate ItemsSource="{Binding SubItems}">
            <TextBlock Text="{Binding Name}" />
        </HierarchicalDataTemplate>
    </TreeView.ItemTemplate>
</TreeView>

public class FileItem
{
    public string Name { get; set; }
    public List<FileItem> SubItems { get; set; }
}

public List<FileItem> GetFileItems(string path)
{
    List<FileItem> fileItems = new List<FileItem>();

    foreach (string directory in Directory.GetDirectories(path))
    {
        FileItem item = new FileItem();
        item.Name = Path.GetFileName(directory);
        item.SubItems = GetFileItems(directory);
        fileItems.Add(item);
    }

    foreach (string file in Directory.GetFiles(path, "*.txt"))
    {
        FileItem item = new FileItem();
        item.Name = Path.GetFileName(file);
        fileItems.Add(item);
    }

    return fileItems;
}

// 在窗口加载时加载文件目录数据
private void Window_Loaded(object sender, RoutedEventArgs e)
{
    treeView.ItemsSource = GetFileItems("文件目录路径");
}

// 当用户选择TreeView中的某个节点时触发
private void treeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
    FileItem selectedItem = (FileItem)treeView.SelectedItem;
    string filePath = "文件目录路径" + selectedItem.Name;

    if (File.Exists(filePath))
    {
        string fileContent = File.ReadAllText(filePath);
        // 处理文件内容
    }
}