init FileBrowser

.gitignore

@@ -0,0 +1,88 @@
+## Ignore Visual Studio temporary files, build results, and
+## files generated by popular Visual Studio add-ons.
+
+# Build results
+[Bb]in/
+[Oo]bj/
+[Ll]og/
+*.user
+*.suo
+*.userosscache
+*.sln.docstates
+
+# .NET Core build results
+project.lock.json
+project.fragment.lock.json
+artifacts/
+
+# Windows image file caches
+Thumbs.db
+ehthumbs.db
+
+# Visual Studio for Mac
+.vscode/
+.idea/
+*.userprefs
+
+# Rider
+*.sln.iml
+
+# Web/ASP.NET (not needed for WPF, but often included)
+*.publish.xml
+*.azurePubxml
+*.azurePubxml.user
+PublishProfiles/
+
+# NuGet
+*.nupkg
+*.snupkg
+.nuget/
+packages/
+*.nuspec
+project.assets.json
+PackageRestoreEnabled.txt
+
+# MSTest test results
+[Tt]est[Rr]esult*/
+[Bb]uild[Ll]og.*
+
+# Visual Studio Code settings
+.vscode/
+
+# Backup & temp files
+*.bak
+*.tmp
+*.temp
+*.log
+
+# Resharper
+_ReSharper*/
+*.DotSettings.user
+
+# Rider
+.idea/
+
+# WPF specific (if generated)
+Generated_Code/
+
+# Local config files
+appsettings.Development.json
+app.config
+web.config
+
+# Crash reports
+*.dmp
+
+# Others
+*.dbmdl
+*.jfm
+*.sdf
+*.cache
+*.pdb
+*.mdb
+
+# Ignore git itself
+.git/
+
+
+.vs/

FileBrowser.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.11.35208.52
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FileBrowser", "FileBrowser\FileBrowser.csproj", "{13CB098D-6CE7-4FC9-8E05-B5D9D3977B88}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{13CB098D-6CE7-4FC9-8E05-B5D9D3977B88}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{13CB098D-6CE7-4FC9-8E05-B5D9D3977B88}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{13CB098D-6CE7-4FC9-8E05-B5D9D3977B88}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{13CB098D-6CE7-4FC9-8E05-B5D9D3977B88}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {567C0FE1-762F-4A8A-8F95-CEE68A3BDCF5}
+	EndGlobalSection
+EndGlobal

FileBrowser/App.xaml

@@ -0,0 +1,9 @@
+<Application x:Class="FileBrowser.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:FileBrowser"
+             Startup="OnStartup">
+    <Application.Resources>
+         
+    </Application.Resources>
+</Application>

FileBrowser/App.xaml.cs

@@ -0,0 +1,30 @@
+using FileBrowser.Services;
+using FileBrowser.ViewModels;
+using Microsoft.Extensions.DependencyInjection;
+using System.Windows;
+
+namespace FileBrowser;
+
+/// <summary>
+/// Interaction logic for App.xaml
+/// </summary>
+public partial class App : Application
+{
+    private IServiceProvider _provider;
+
+    private void OnStartup(object sender, StartupEventArgs e)
+    {
+        var services = new ServiceCollection();
+
+        services.AddSingleton<IFileService, FileService>();
+        services.AddSingleton<MainViewModel>();
+        services.AddTransient<MainWindow>(); // window created with DI
+
+        _provider = services.BuildServiceProvider();
+
+        var wnd = _provider.GetRequiredService<MainWindow>();
+        // Set DataContext with DI-provided VM (no code-behind in view)
+        wnd.DataContext = _provider.GetRequiredService<MainViewModel>();
+        wnd.Show();
+    }
+}

FileBrowser/AssemblyInfo.cs

@@ -0,0 +1,10 @@
+using System.Windows;
+
+[assembly: ThemeInfo(
+    ResourceDictionaryLocation.None,            //where theme specific resource dictionaries are located
+                                                //(used if a resource is not found in the page,
+                                                // or application resource dictionaries)
+    ResourceDictionaryLocation.SourceAssembly   //where the generic resource dictionary is located
+                                                //(used if a resource is not found in the page,
+                                                // app, or any theme specific resource dictionaries)
+)]

FileBrowser/FileBrowser.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net8.0-windows</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <UseWPF>true</UseWPF>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="9.0.8" />
+  </ItemGroup>
+
+</Project>

FileBrowser/Helpers/RelayCommand.cs

@@ -0,0 +1,21 @@
+using System.Windows.Input;
+
+namespace FileBrowser.Helpers;
+
+public class RelayCommand : ICommand
+{
+    private readonly Action<object?> _execute;
+    private readonly Func<object?, bool>? _canExecute;
+
+    public RelayCommand(Action<object?> execute, Func<object?, bool>? canExecute = null)
+    {
+        _execute = execute ?? throw new ArgumentNullException(nameof(execute));
+        _canExecute = canExecute;
+    }
+
+    public bool CanExecute(object? parameter) => _canExecute?.Invoke(parameter) ?? true;
+    public void Execute(object? parameter) => _execute(parameter);
+
+    public event EventHandler? CanExecuteChanged;
+    public void RaiseCanExecuteChanged() => CanExecuteChanged?.Invoke(this, EventArgs.Empty);
+}

FileBrowser/MainWindow.xaml

@@ -0,0 +1,73 @@
+<Window x:Class="FileBrowser.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:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:local="clr-namespace:FileBrowser"
+        mc:Ignorable="d"
+        Title="Keyboard File Browser" Height="600" Width="1000">
+    <Window.InputBindings>
+        <!-- Tab: Enter / Open -->
+        <KeyBinding Key="Tab" Command="{Binding EnterCommand}" />
+        <!-- Shift+Tab: Up one folder -->
+        <KeyBinding Key="Tab" Modifiers="Shift" Command="{Binding UpCommand}" />
+        <!-- F5 refresh -->
+        <KeyBinding Key="F5" Command="{Binding RefreshCommand}" />
+    </Window.InputBindings>
+
+    <DockPanel LastChildFill="True" Margin="6">
+        <!-- Top: Path -->
+        <TextBlock DockPanel.Dock="Top" Text="{Binding CurrentPath}" d:Text="c:/Test" FontWeight="Bold"
+                   Padding="4" />
+
+        <Grid>
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="2*" />
+                <ColumnDefinition Width="4*" />
+                <ColumnDefinition Width="3*" />
+            </Grid.ColumnDefinitions>
+
+            <!-- Left: Parent folder contents -->
+            <Border Grid.Column="0" BorderBrush="Gray" BorderThickness="1" Margin="4"
+                    Padding="4">
+                <StackPanel>
+                    <TextBlock Text="Parent / Siblings" FontWeight="SemiBold" />
+                    <ListBox ItemsSource="{Binding ParentItems}"
+                             SelectedItem="{Binding SelectedParentItem}"
+                             DisplayMemberPath="Name"
+                             KeyboardNavigation.TabNavigation="Local"
+                             Focusable="False" />
+                </StackPanel>
+            </Border>
+
+            <!-- Middle: Current folder contents and filter input (keyboard-only) -->
+            <Border Grid.Column="1" BorderBrush="Gray" BorderThickness="1" Margin="4"
+                    Padding="4">
+                <DockPanel>
+                    <TextBlock DockPanel.Dock="Top" Text="Current Folder (type to filter)" />
+                    <!-- Hidden TextBox takes all typing for filter -->
+                    <TextBox x:Name="FilterBox"
+                             Text="{Binding FilterText, UpdateSourceTrigger=PropertyChanged}"
+                             Height="0.0" Opacity="0" Focusable="True"/>
+                    <ListBox ItemsSource="{Binding CurrentView}"
+                             SelectedItem="{Binding SelectedItem, Mode=TwoWay}"
+                             DisplayMemberPath="Name"
+                             IsSynchronizedWithCurrentItem="True"
+                             KeyboardNavigation.TabNavigation="Local" />
+                </DockPanel>
+            </Border>
+
+            <!-- Right: Preview -->
+            <Border Grid.Column="2" BorderBrush="Gray" BorderThickness="1" Margin="4"
+                    Padding="4">
+                <StackPanel>
+                    <TextBlock Text="Preview" FontWeight="SemiBold" />
+                    <ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto">
+                        <!-- Einfacher Text-Preview -->
+                        <TextBlock Text="{Binding PreviewText}" TextWrapping="Wrap" />
+                    </ScrollViewer>
+                </StackPanel>
+            </Border>
+        </Grid>
+    </DockPanel>
+</Window>

FileBrowser/MainWindow.xaml.cs

@@ -0,0 +1,14 @@
+using System.Windows;
+
+namespace FileBrowser;
+
+/// <summary>
+/// Interaction logic for MainWindow.xaml
+/// </summary>
+public partial class MainWindow : Window
+{
+    public MainWindow()
+    {
+        InitializeComponent();
+    }
+}

FileBrowser/Models/FileItem.cs

@@ -0,0 +1,10 @@
+using System.IO;
+
+namespace FileBrowser.Models;
+
+public class FileItem
+{
+    public string FullPath { get; set; }
+    public string Name => Path.GetFileName(FullPath) ?? FullPath;
+    public bool IsDirectory => Directory.Exists(FullPath);
+}

FileBrowser/Services/FileService.cs

@@ -0,0 +1,51 @@
+using FileBrowser.Models;
+using System.IO;
+
+namespace FileBrowser.Services;
+
+public class FileService : IFileService
+{
+    public string GetParentDirectory(string path)
+    {
+        try
+        {
+            var di = Directory.GetParent(path);
+            return di?.FullName ?? path;
+        }
+        catch { return path; }
+    }
+
+    public IEnumerable<FileItem> GetDirectoryItems(string path)
+    {
+        try
+        {
+            var dirs = Directory.EnumerateDirectories(path)
+                .Select(d => new FileItem { FullPath = d });
+            var files = Directory.EnumerateFiles(path)
+                .Select(f => new FileItem { FullPath = f });
+            return dirs.Concat(files).OrderBy(i => i.IsDirectory ? 0 : 1).ThenBy(i => i.Name);
+        }
+        catch { return Array.Empty<FileItem>(); }
+    }
+
+    public string? ReadTextPreview(string path, int maxChars = 20000)
+    {
+        try
+        {
+            var ext = Path.GetExtension(path)?.ToLowerInvariant();
+            var textExts = new[] { ".txt", ".cs", ".config", ".json", ".xml", ".log", ".md", ".csv" };
+            if (!textExts.Contains(ext)) return null;
+            using var sr = new StreamReader(path);
+            var s = sr.ReadToEnd();
+            if (s.Length > maxChars) s = s.Substring(0, maxChars) + "\n... (truncated)";
+            return s;
+        }
+        catch { return null; }
+    }
+
+    public bool IsImage(string path)
+    {
+        var ext = Path.GetExtension(path)?.ToLowerInvariant();
+        return ext == ".png" || ext == ".jpg" || ext == ".jpeg" || ext == ".bmp" || ext == ".gif";
+    }
+}

FileBrowser/Services/IFileService.cs

@@ -0,0 +1,11 @@
+using FileBrowser.Models;
+
+namespace FileBrowser.Services;
+
+public interface IFileService
+{
+    string GetParentDirectory(string path);
+    IEnumerable<FileItem> GetDirectoryItems(string path);
+    string? ReadTextPreview(string path, int maxChars = 20000);
+    bool IsImage(string path);
+}

FileBrowser/ViewModels/MainViewModel.cs

@@ -0,0 +1,242 @@
+using FileBrowser.Helpers;
+using FileBrowser.Models;
+using FileBrowser.Services;
+using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Diagnostics;
+using System.IO;
+using System.Windows.Data;
+using System.Windows.Input;
+
+namespace FileBrowser.ViewModels;
+
+public class MainViewModel : INotifyPropertyChanged
+{
+    private readonly IFileService _fileService;
+
+    public MainViewModel(IFileService fileService)
+    {
+        _fileService = fileService ?? throw new ArgumentNullException(nameof(fileService));
+
+        ParentItems = new ObservableCollection<FileItem>();
+        CurrentItems = new ObservableCollection<FileItem>();
+
+        // Commands zuerst initialisieren
+        EnterCommand = new RelayCommand(_ => EnterOrOpen(), _ => SelectedItem != null);
+        UpCommand = new RelayCommand(_ => Up(), _ => CanGoUp());
+        RefreshCommand = new RelayCommand(_ => Refresh());
+
+        // CollectionView danach erzeugen
+        _currentView = CollectionViewSource.GetDefaultView(CurrentItems);
+        if (_currentView != null)
+            _currentView.Filter = FilterPredicate;
+
+        // Defaults
+        CurrentPath = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) ?? @"C:\";
+        FilterText = string.Empty;
+
+        // Jetzt sicher Refresh aufrufen (SelectedItem kann gesetzt werden ohne Nullref)
+        try { Refresh(); }
+        catch (Exception ex) { Debug.WriteLine("Initial Refresh failed: " + ex); }
+    }
+
+    public event PropertyChangedEventHandler? PropertyChanged;
+    private void Raise(string name) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
+
+    private string _currentPath = "";
+    public string CurrentPath
+    {
+        get => _currentPath;
+        set
+        {
+            if (_currentPath == value) return;
+            _currentPath = value;
+            Raise(nameof(CurrentPath));
+            Refresh();
+        }
+    }
+
+    public ObservableCollection<FileItem> ParentItems { get; } = new ObservableCollection<FileItem>();
+    public ObservableCollection<FileItem> CurrentItems { get; } = new ObservableCollection<FileItem>();
+
+    private ICollectionView _currentView;
+    public ICollectionView CurrentView => _currentView;
+
+    private FileItem? _selectedParentItem;
+    public FileItem? SelectedParentItem
+    {
+        get => _selectedParentItem;
+        set
+        {
+            _selectedParentItem = value;
+            if (value != null)
+            {
+                // selecting a sibling sets CurrentPath to its parent (no auto-enter)
+            }
+            Raise(nameof(SelectedParentItem));
+        }
+    }
+
+    private FileItem? _selectedItem;
+    public FileItem? SelectedItem
+    {
+        get => _selectedItem;
+        set
+        {
+            _selectedItem = value;
+            UpdatePreview();
+            Raise(nameof(SelectedItem));
+            // Sicherstellen, dass EnterCommand existiert und vom erwarteten Typ ist,
+            // bevor RaiseCanExecuteChanged aufgerufen wird.
+            if (EnterCommand is RelayCommand rc)
+            {
+                rc.RaiseCanExecuteChanged();
+            }
+        }
+    }
+
+    private string? _previewText;
+    public string? PreviewText
+    {
+        get => _previewText;
+        set { _previewText = value; Raise(nameof(PreviewText)); }
+    }
+
+    private string _filterText = "";
+    public string FilterText
+    {
+        get => _filterText;
+        set
+        {
+            _filterText = value;
+            _currentView.Refresh();
+            Raise(nameof(FilterText));
+        }
+    }
+
+    private bool FilterPredicate(object obj)
+    {
+        if (obj is FileItem fi)
+        {
+            if (string.IsNullOrEmpty(FilterText)) return true;
+            return fi.Name.IndexOf(FilterText, StringComparison.OrdinalIgnoreCase) >= 0;
+        }
+        return true;
+    }
+
+    private void UpdatePreview()
+    {
+        PreviewText = null;
+        if (SelectedItem == null) return;
+
+        // Schütze _fileService gegen Null
+        if (_fileService == null) return;
+
+        if (SelectedItem.IsDirectory) return;
+
+        var txt = _fileService.ReadTextPreview(SelectedItem.FullPath);
+        if (txt != null)
+        {
+            PreviewText = txt;
+            return;
+        }
+
+        if (_fileService.IsImage(SelectedItem.FullPath))
+        {
+            PreviewText = SelectedItem.FullPath;
+        }
+    }
+
+    public ICommand EnterCommand { get; }
+    public ICommand UpCommand { get; }
+    public ICommand RefreshCommand { get; }
+
+    private void Refresh()
+    {
+        // Defensive programming to avoid NullReferenceExceptions
+        if (ParentItems == null || CurrentItems == null)
+            throw new InvalidOperationException("Collections were not initialized.");
+
+        // clear existing
+        ParentItems.Clear();
+        CurrentItems.Clear();
+
+        // normalize CurrentPath
+        var path = string.IsNullOrWhiteSpace(CurrentPath) ? Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) : CurrentPath;
+
+        // Determine parent folder for sibling listing; if none, use the same path
+        string parentForSiblings;
+        try
+        {
+            var parentDirInfo = Directory.GetParent(path);
+            parentForSiblings = parentDirInfo?.FullName ?? path;
+        }
+        catch (Exception ex)
+        {
+            Debug.WriteLine("Directory.GetParent failed: " + ex);
+            parentForSiblings = path;
+        }
+
+        // Get items safely from service (service should itself be robust)
+        IEnumerable<FileItem> parentItems;
+        try { parentItems = _fileService.GetDirectoryItems(parentForSiblings) ?? Array.Empty<FileItem>(); }
+        catch (Exception ex) { Debug.WriteLine("GetDirectoryItems(parent) failed: " + ex); parentItems = Array.Empty<FileItem>(); }
+
+        foreach (var item in parentItems) ParentItems.Add(item);
+
+        IEnumerable<FileItem> currentItems;
+        try { currentItems = _fileService.GetDirectoryItems(path) ?? Array.Empty<FileItem>(); }
+        catch (Exception ex) { Debug.WriteLine("GetDirectoryItems(current) failed: " + ex); currentItems = Array.Empty<FileItem>(); }
+
+        foreach (var item in currentItems) CurrentItems.Add(item);
+
+        // Refresh view safely
+        try { _currentView?.Refresh(); }
+        catch (Exception ex) { Debug.WriteLine("CollectionView.Refresh failed: " + ex); }
+
+        // Select first available safely
+        SelectedItem = CurrentItems.FirstOrDefault();
+        SelectedParentItem = ParentItems.FirstOrDefault(o => o.FullPath.Contains(CurrentPath.TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)));
+
+        // Notify (collections changed notifications come from ObservableCollection,
+        // but we raise to be safe)
+        Raise(nameof(ParentItems));
+        Raise(nameof(CurrentItems));
+        Raise(nameof(CurrentView));
+    }
+
+    private bool CanGoUp() => Directory.GetParent(CurrentPath) != null;
+
+    private void Up()
+    {
+        var parent = Directory.GetParent(CurrentPath)?.FullName;
+        if (parent != null)
+        {
+            CurrentPath = parent;
+            FilterText = "";
+        }
+    }
+
+    private void EnterOrOpen()
+    {
+        if (SelectedItem == null) return;
+        if (SelectedItem.IsDirectory)
+        {
+            CurrentPath = SelectedItem.FullPath;
+            FilterText = "";
+        }
+        else
+        {
+            try
+            {
+                ProcessStartInfo psi = new ProcessStartInfo
+                {
+                    FileName = SelectedItem.FullPath,
+                    UseShellExecute = true
+                };
+                Process.Start(psi);
+            }
+            catch { /* ignore failures */ }
+        }
+    }
+}