Build Tree View and Bind in WPF using Recursive Function

public sealed class ItemGroup : NotifyPropertyChanged
{
private int _GPID;
public int GPID
{
get { return _GPID; }
set
{
_GPID = value;
RaiseNotifyPropertyChange("GPID");
}
}
private string _Name;
public string Name
{
get { return _Name; }
set
{
_Name = value;
RaiseNotifyPropertyChange("Name");
}
}
List<ItemGroup> _chld = new List<ItemGroup>();
public List<ItemGroup> Chld
{
get { return _chld; }
set
{
_chld = value;
RaiseNotifyPropertyChange("Chld");
}
}
}

public ObservableCollection<ItemGroup> Items { get; set; }

private void BuildTree(ObservableCollection<ItemGroup> objTreeView)
{
if (dt != null)
{
foreach (DataRow dataRow in dt.Rows)
{
if (Convert.ToInt32(dataRow["GPID"]) == 0)
{
var obj = new ItemGroup();
obj.Name = dataRow["Name"].ToString();
foreach (ItemGroup childnode in GetChildNode(Convert.ToInt64(dataRow["GID"])))
{
obj.Chld.Add(childnode);
}
objTreeView.Add(obj);
}
}
}
}
private List<ItemGroup> GetChildNode(long parentid)
{
List<ItemGroup> childtreenodes = new List<ItemGroup>();
DataRow[] tmptbl = dt.Select("GPID = " + parentid);
foreach (DataRow dataRow in tmptbl)
{
ItemGroup childNode = new ItemGroup();
childNode.Name = dataRow["Name"].ToString();
foreach (ItemGroup cnode in GetChildNode(Convert.ToInt64(dataRow["GID"])))
{
childNode.Chld.Add(cnode);
}
childtreenodes.Add(childNode);
}
return childtreenodes;
}

<Window x:Class="TreeView.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:self="clr-namespace:TreeView"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<self:MainWindowViewModel></self:MainWindowViewModel>
</Window.DataContext>
<Grid Margin="10">
<TreeView Grid.Row="3" Name="trbMenu" ItemsSource="{Binding Items}">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate DataType="{x:Type self:ItemGroup}" ItemsSource="{Binding Chld}">
<TextBlock Text="{Binding Name}" />
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
</Grid>
</Window>