HierarchicalDataTemplate with Treeview in MVVM - wpf

Question

I'm relatively new to MVVM and WPF. I'm attempting to fill a TreeView control with a directory and it's files / subdirectories (in effect the contents of a zip file that I have unpacked)
Following along after this SO question, I have the following class:
namespace IFR_Full.Model
{
public class Item
{
public string Name { get; set; }
public string Path { get; set; }
}
public class FileItem : Item
{
}
public class DirectoryItem : Item
{
public List<Item> Items { get; set; }
public DirectoryItem()
{
Items = new List<Item>();
}
}
public class TVItemProvider
{
public List<Item> GetItems(string path)
{
var items = new List<Item>();
var dirInfo = new DirectoryInfo(path);
foreach (var directory in dirInfo.GetDirectories())
{
var item = new DirectoryItem
{
Name = directory.Name,
Path = directory.FullName,
Items = GetItems(directory.FullName)
};
items.Add(item);
}
foreach (var file in dirInfo.GetFiles())
{
var item = new FileItem
{
Name = file.Name,
Path = file.FullName
};
items.Add(item);
}
return items;
}
}
}
In my ViewModel class I have these properties:
TVItemProvider TVIP = new TVItemProvider();
private List<Item> _tvitems;
public List<Item> TVItems
{
get { return _tvitems; }
}
which is created in this method:
private void LoadIDMLTreeView(string path)
{
_tvitems = TVIP.GetItems(path);
}
I set the header and DataContext of my MainWindow like this:
...
xmlns:ViewModel="clr-namespace:IFR_Full"
xmlns:Model ="clr-namespace:IFR_Full.Model"
...
<Window.DataContext>
<ViewModel:ExcelImportViewModel/>
</Window.DataContext>
and set my treeview xaml code like this:
<TreeView ItemsSource="{Binding}" Name="IDMLView" Margin="10,171.74,10,8" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type Model:DirectoryItem}" ItemsSource="{Binding Path=TVItems}">
<TextBlock Text="{Binding Path=Name}" ToolTip="{Binding Path=Path}" />
</HierarchicalDataTemplate>
<DataTemplate DataType="{x:Type Model:FileItem}">
<TextBlock Text="{Binding Path=Name}" ToolTip="{Binding Path=Path}" />
</DataTemplate>
</TreeView.Resources>
</TreeView>
When I run the program in debug mode I can see that TVItems contains the appropriate items (Directories and files), but my TreeView control is blank.
I imagine that the issue is with the bindings?

Answer 1

Change <TreeView ItemsSource="{Binding}" ... to <TreeView ItemsSource="{Binding TVItems}" ...
Also , Change to <HierarchicalDataTemplate DataType="{x:Type local:DirectoryItem}" ItemsSource="{Binding Items}" >
Your class has to be like this :
public class TVItemProvider
{
List<object> items = new List<object>();
DirectoryInfo dirInfo;
public List<object> GetItems(string path)
{
dirInfo = new DirectoryInfo(path);
foreach (var directory in dirInfo.GetDirectories())
{
var item = new DirectoryItem
{
Name = directory.Name,
Path = directory.FullName,
Items = new TVItemProvider().GetItems(directory.FullName)
};
items.Add(item);
}
foreach (var file in dirInfo.GetFiles())
{
var item = new FileItem
{
Name = file.Name,
Path = file.FullName
};
items.Add(item);
}
return items;
}
}
Finally change the type of your lists to List<object> (all of them)
Hope it would help