Hi Rob

Thanks for looking into this so quickly.

I done few changes in your attached solution and managed to replicate issue at my end.

To reproduce, you can do these changes-

1. Change ViewModel like below-

public class MainWindowViewModel
    {
        public ObservableCollection<StaffMember> StaffMembers { get; set; }

        public MainWindowViewModel()
        {
            //Moved your code to method as it will generated during runtime
        }

        public void GenerateData()
        {
            StaffMembers = new ObservableCollection<StaffMember>();
            StaffMembers.Add(new StaffMember { StaffCategory = "category1", StaffTypes = "type1", Staff = new List<Staff>() });
            StaffMembers[0].Staff.Add(new Staff { Name = "staff1", Value = "value1" });
            StaffMembers[0].Staff.Add(new Staff { Name = "staff2", Value = "value1" });
            StaffMembers[0].Staff.Add(new Staff { Name = "staff3", Value = "value1" });
            StaffMembers[0].Staff.Add(new Staff { Name = "staff4", Value = "value1" });

            StaffMembers.Add(new StaffMember { StaffCategory = "category2", StaffTypes = "type2", Staff = new List<Staff>() });
            StaffMembers[1].Staff.Add(new Staff { Name = "staff1", Value = "value2" });
            StaffMembers[1].Staff.Add(new Staff { Name = "staff2", Value = "value2" });
            StaffMembers[1].Staff.Add(new Staff { Name = "staff3", Value = "value2" });
            StaffMembers[1].Staff.Add(new Staff { Name = "staff4", Value = "value2" });

            StaffMembers.Add(new StaffMember { StaffCategory = "category3", StaffTypes = "type3", Staff = new List<Staff>() });
            StaffMembers[2].Staff.Add(new Staff { Name = "staff1", Value = "value3" });
            StaffMembers[2].Staff.Add(new Staff { Name = "staff2", Value = "value3" });
            StaffMembers[2].Staff.Add(new Staff { Name = "staff3", Value = "value3" });
            StaffMembers[2].Staff.Add(new Staff { Name = "staff4", Value = "value3" });
        }
    }

2. Call ViewModel method from button click (refer 1st statement in button click)

private void Button_Click(object sender, RoutedEventArgs e)
        {
            ((MainWindowViewModel)this.DataContext).GenerateData();

            var staffMember = this.ViewModel.StaffMembers.First();

            for (Int32 i = 0; i < staffMember.Staff.Count; i++)
            {
                var field = new UnboundField
                {
                    Name = staffMember.Staff[i].Name,
                    BindingMode = BindingMode.TwoWay,
                    BindingPath = new PropertyPath(String.Format("Staff[{0}].Value", i))
                };

                field.Settings.EditAsType = typeof(String);
                xdg.FieldLayouts[0].Fields.Add(field);
            }
        }

Please let me know your thoughts.

Cheers
Sagar

Hi Sagar,

In my sample it doesn't work because I didn't implement INotifyPropertyChanged on the StaffMembers collection.  The StaffMembers collection is not instantiated until GenerateData is called so when the XamDataGrid binds to it, its currently null.  Now when the button is clicked it creates the StaffMembers instance but it never notifies the datagrid that the datasource has been updated.  If I implement INotifyPropertyChanged on the property then the above code changes you made will work.

private ObservableCollection<StaffMember> _staffMembers;
public ObservableCollection<StaffMember> StaffMembers
{
    get { return _staffMembers; }
    set
    {
        if (_staffMembers != value)
        {
            _staffMembers = value;
            OnPropertyChanged("StaffMembers");
        }
    }
}

If you haven't implemented INotifyPropertyChanged on your properties then that is most likely why your columns do not appear.  The XamDataGrid still thinks it has a null DataSource.

Hi Rob

Yes, you are correct. Implementing INotifyPropertyChanged does resolve the problem.

Can I ask one more sample in this regards? Is there is way to move code from button click event to View Model? I do not want to keep code in MainWindow.xaml.cs file.

Cheers
Sagar

Hi Rob,

I still didn't manage to complete using last idea. so I am going with earlier solution.

Thanks for sharing these details.

Cheers

Sagar