WPF: SelectedItem Binding Not Showing With DisplayMemberPath - wpf

Question

I've got a ComboBox (inside a ListView) that used to be tied to a collection of strings. However, I'm switching to having it use a custom class instead.
Now the ComboBox is bound to an ObservableCollection of type Area. For display, I'm showing the Name property with DisplayMemberPath. This works great, but the box is no longer loading with the current value selected.
<ListView x:Name="TestListView" ItemsSource="{Binding TestViewList, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
<ListView.View>
<GridView>
<GridViewColumn Header="Area">
<GridViewColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding DataContext.AreaList, ElementName=BVTWindow}" DisplayMemberPath="Name" SelectedItem="{Binding Path=Area, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" />
public ObservableCollection<ViewTest> TestViewList { get; private set; }
public ObservableCollection<Area> AreaList { get; private set; }
public class ViewTest : BindableBase
{
public string Description { get; set; }
public Area Area { get; set; }
}
public partial class Area
{
public long ID { get; set; }
public string Name { get; set; }
}
"Area" is the same class as the Collection, and is a property of the class the ListView's ItemsSource is bound to. Am I doing this the right way? Any help is much appreciated.
UPDATE:
I had a theory that perhaps using the "Name" property (which is a string) for display in the box made the SelectedItem attribute look for a string rather than something of type Area. I changed the class for TestViewList to use a string to keep track of Area, but that didn't change the program's behavior at all.
UPDATE 2:
Above, I've added the pertinent lines from the view model related to the ComboBox and ListView in question.
Update 3:
I've changed my Area property from inline to expanded, including the SetProperty that handles raising. It now works for new items added to the ItemSource at run-time, but is still a blank selection for on items loaded at program start.
public class ViewTest : BindableBase
{
public string Description { get; set; }
public Area Area
{
get
{
return this.area;
}
set
{
this.SetProperty(ref this.area, value);
}
}
}
Update 4:
It turns out Paul Gibson's answer was correct. The reason my existing entries weren't loading properly had to do with a logic error in the way I was loading items from the database, and not a problem with the xaml bindings. Everything works now (with respect to those ComboBoxes, at least).

Answer 1

Based on what you are saying I think my comment is the answer. This is the case for a single combobox. In your case you need one for every line of the grid, so you may have to programatically add the binding to members of a list by index.
In your view model if you also have (single case):
private Area _curSelArea;
public Area curSelArea
{
get { return _curSelArea; }
set
{
_curSelArea = value;
RaisePropertyChanged("curSelArea");
}
}
Then you can bind to the property with:
SelectedItem="{Binding DataContext.curSelArea . . . }"
The view model can set the initial value of curSelArea if it is known initially.
EDIT: After actually having to do this I found that someone extended the DataGridComboBoxColumn to facilitate better binding. Check out this link if you are trying to do this: http://joemorrison.org/blog/2009/02/17/excedrin-headache-35401281-using-combo-boxes-with-the-wpf-datagrid/