CollectionView not updating - mvvm

Question

I have a CollectionView set up in the View as:
<CollectionView ItemsSource="{Binding Staffmembers}">
<CollectionView.ItemTemplate>
<DataTemplate >
...
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
The ViewModel defines the Staffmembers ItemsSource as an observable collection:
public StaffViewModel()
{
Staffmembers = new ObservableCollection<Staff>(App.StaffRepo.GetStaff());
}
[ObservableProperty]
ObservableCollection<Staff> staffmembers;
When I add a new item to this collection it is supposed to update
public void AddStaff()
{
Staffmember.Name= name;
Staffmember.Surname= surname;
Staffmember.Role= role;
try
{
App.StaffRepo.SaveStaff(Staffmember);
Staffmembers = new ObservableCollection<Staff>(App.StaffRepo.GetStaff());
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
Shell.Current.GoToAsync("//Staff");
}
The problem is that when I add to the collection, the change isn't reflected in the CollectionView. If I reload the collection, the change shows up, but I want it to reflect immediately. I've seen this done in tutorials but I'm just not sure what I'm missing

Answer 1

The problem is that you do this in the AddStaff method: Staffmembers = new ObservableCollection<Staff>(App.StaffRepo.GetStaff());.
Once you created a new ObservableCollection you should clear it and repopulate it (or just add a single record, however you want to add new things). If you create a new instance it will lose the data binding connection and will stop updating the UI.
So change it into something like this:
public void AddStaff()
{
Staffmember.Name= name;
Staffmember.Surname= surname;
Staffmember.Role= role;
try
{
App.StaffRepo.SaveStaff(Staffmember);
Staffmembers.Clear();
foreach(var member in App.StaffRepo.GetStaff())
Staffmembers.Add(member);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
Shell.Current.GoToAsync("//Staff");
}

Answer 2

This code below might cause the ObservableCollection not work.
App.StaffRepo.SaveStaff(Staffmember);
Staffmembers = new ObservableCollection<Staff>(App.StaffRepo.GetStaff());
You should add the data to the ObservableCollection directly.
Such as
Staffmembers = new ObservableCollection<Staff>();
Staffmembers.Add(new Staff { Name = "1" });