WPF MVVM Listview itemsource binding with list in a class property - wpf

Question

I have a page with two parts :
A Listview with itemsource binded with a class, ObservableCollection "Patients" loaded with "Patient" class.
Under the Listview are Textboxes binded with the selecteditem Patient. Everything works without writing any code in the page, except in selection_changed to scroll to selected item.
A second Listview must display the details "Visites" from the selected "Patient".
The application works in a MVVM Framework with a Viewmodel containing the properties for the page.
The problem is to make the relation between the two ListView. I tried first building the second list "Visites" in the NotifyPropertyChanged event :
if (Patient.ID > 0)
{
LoadVisite(Patient.ID); // fill the details list "Visites"
NotifyPropertyChanged("Visites");
}
No delail is shown when "Patient" is selected.
I tried another solution inserting the list of details in the master class "Patient like this :
public Class Patient
...
public ObservableCollection<ClsVisite> Visites
{
get
{
return _visites;
}
set
{
_visites = value;
}
}
// WDABase class to open the database and load data connection
WDABase wd = new WDABase();
wd.LoadListeVisites(ID, _visites); //ID is the relation beween the two tables
}
}
Now I try to create the Listview detail itemsource in the XAML like this :
<ListView Name="ListeVisites" ItemsSource="{Binding Path=Patient.Visites}" SelectedItem="{Binding Visite}">
No details where shown.
The unique solution I found was to add some code in the selection_changed event of the master Listview like this (in this case the listviews are in two different frame) :
private void ListePatients_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
ListePatients.ScrollIntoView(ListePatients.SelectedItem);
if(ListePatients.SelectedItem != null)
{
var w1 = ((System.Windows.FrameworkElement)App.Current.MainWindow.Content).Parent;
Frame pageVisite = (w1 as MainWindow).Visit;
var w2 = (System.Windows.FrameworkElement)pageVisite.Content;
ListView Lv = (w2 as Visite).ListeVisites;
Lv.ItemsSource = (ListePatients.SelectedItem as ClsPatient).Visites;
}
}
And it's works but is there another elegant solution to bind the itemsource of the details Listview ?
Thanks for helping me.
Jean-Marie

Answer 1

I found the solution to my problem.
The Reason the details were not displayed is because the frame used for the listview is not common with the master frame.
I discover that when I display the details frame the "Patient" object contains only null. I Don't know why but I read about sharing ViewModel and now I use a common one in App.xaml and I Don't need to specify the itemsource for the details Listview in code. I put in XAML itemsource={Binding Patient.Visites} and everything works.