WPF TreeView MVVM using HierarchicalDataTemplate is strange updating like same word

Question

I want to show user's Folder (C:\Food\BBQ\Recipe\Recipefile.txt)

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like that but result is ...

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I make a project MVVM patteron wpf Using ViewModel.cs and View with HierarchicalDataTemplate

this is my codes

window1.xaml

<Window.Resources>
    <ObjectDataProvider x:Key="ObjectDataProviderKey">
        <ObjectDataProvider.ObjectInstance>
            <vm:FolderViewModel  FullPath="C:\Food"/>
        </ObjectDataProvider.ObjectInstance>
    </ObjectDataProvider>
    <HierarchicalDataTemplate
        DataType="{x:Type vm:FolderViewModel}"
        ItemsSource="{Binding Path=SubFolderCollection}">
        <TextBlock Text="{Binding Path=Name}" />
    </HierarchicalDataTemplate>


<TreeView Name="folderTreeView" Grid.ColumnSpan="2" Grid.Row="2">
        <TreeViewItem
            Header="Favorit"
            ItemsSource="{Binding Source={StaticResource ObjectDataProviderKey}, Path=SubFolderCollection}" />
    </TreeView>

and viewModel FolderViewModel.cs

 namespace TEST.ViewModels.TreeView
{
    public class FolderViewModel : INotifyPropertyChanging
    {
        namespace TEST.ViewModels.TreeView
        {
        public class FolderViewModel : INotifyPropertyChanging
        {
            #region Field


            private DirectoryInfo directoryInfo;
            private ObservableCollection<FolderViewModel> subFolderCollection;


            private ObservableCollection<FileInfo> fileInfoCollection;

            #endregion


            #region  - FullPath


            public string FullPath
            {
                get
                {
                    return directoryInfo.FullName;
                }

                set
                {
                    if (Directory.Exists(value))
                    {
                        directoryInfo = new DirectoryInfo(value);
                    }
                    else
                    {
                        throw new ArgumentException("No exist.", "FullPath");
                    }
                }
            }

            #endregion
            #region  - Name


            private string _Name = string.Empty;

            public event PropertyChangingEventHandler PropertyChanging;

            public string Name
            {
                get
                {
                    _Name = directoryInfo.Name;
                    return _Name;
                }

                set
                {
                    _Name = value;
                    OnpropertyChanaged("Name");
                }
            }

            private void OnpropertyChanaged(string v)
            {
                throw new NotImplementedException();
            }



            #endregion
            #region  - SubFolderCollection


            public ObservableCollection<FolderViewModel> SubFolderCollection
            {
                get
                {
                    if (subFolderCollection == null)
                    {
                        subFolderCollection = new ObservableCollection<FolderViewModel>();

                        DirectoryInfo[] directoryInfoArray = directoryInfo.GetDirectories();

                        //DirectoryInfo[] directoryInfoArray = (DirectoryInfo[])this.directoryInfo.GetFileSystemInfos();
                        for (int i = 0; i < directoryInfoArray.Length; i++)
                        {
                            FolderViewModel folder = new FolderViewModel();
                            FullPath = directoryInfoArray[i].FullName;

                            this.subFolderCollection.Add(folder);
                        }
                    }

                    return subFolderCollection;
                }
            } 
            #endregion
            #region  FileInfoCollection


            public ObservableCollection<FileInfo> FileInfoCollection
            {
                get
                {
                    if (this.fileInfoCollection == null)
                    {
                        this.fileInfoCollection = new ObservableCollection<FileInfo>();

                        FileInfo[] fileInfoArray = this.directoryInfo.GetFiles();

                        for (int i = 0; i < fileInfoArray.Length; i++)
                        {
                            this.fileInfoCollection.Add(fileInfoArray[i]);
                        }
                    }

                    return this.fileInfoCollection;
                }
            }

            #endregion

            #region  - Folder()

            public FolderViewModel()
            {
                FullPath = @"C:\Food\";
            }

            #endregion
        }
    }

what should i do ??

Answer 1

If I understood you correctly. To Achieive the way you wanted you can do something like this.
MainWindow.xaml

 <TreeView ItemsSource="{Binding TreeModel}">
        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding Child}">
                <Grid>
                    <Label Content="{Binding Name}"/>
                </Grid>
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>
    </TreeView>

And Then your ViewModel you can create a collection which goes through your folders and add folder and file name

MainViewModel.cs

   public ObservableCollection<DirModel> TreeModel { get; set; }
   
    public MainViewModel()
    {
        TreeModel = new ObservableCollection<DirModel>();
        Load();
    }

    void Load()
    {
        var root = "C:\\TEST";
        foreach (var dirInfo in new DirectoryInfo(root).GetDirectories())
        {
            var dir = new DirModel() { Name = dirInfo.Name };
            foreach (var sb in dirInfo.GetDirectories())
            {
                var sDir = new ChildDirModel() { Name = sb.Name };
                var sFile = new FileModel() { Name = sb.GetFiles().First().Name };
                sDir.Child.Add(sFile);
                dir.Child.Add(sDir);
            }
            TreeModel.Add(dir);
        }
    }

Finally create a Model class which represent your structure

public class DirModel
{
    public string Name { get; set; }

    public ObservableCollection<ChildDirModel> Child { get; set; }

    public DirModel()
    {
        Child = new ObservableCollection<ChildDirModel>();
    }
}

public class ChildDirModel
{
    public string Name { get; set; }

    public ObservableCollection<FileModel> Child { get; set; }

    public ChildDirModel()
    {
        Child = new ObservableCollection<FileModel>();
    }
}

public class FileModel
{
    public string Name { get; set; }
}

Your application will look like this