Change value in row will make it disappear

[John]

I have a issue I haven't found any solution for so far and hopefully you can help me. 
I have a GridView that I bind a IEnumerable<MyViewModel> to. I have a few static resources as well to be able to get the 
GridViewComboBoxColumn to work. 


This issue is that when I initially load my data and bind it, it all looks just fine. When I then select a row, edit a value
and then click on an other row, the row with the edited value will disappear. If I reload the data I can see all the rows again,
but this issue will always happen every time I reload and the data is rebounded.

Edit: This will only happen for the changes for the very first row I change values in as well. When that row is gone, I can change the other rows with no issues at all. 

Edit2: This seems to happen when I have a binding to my ViewModel. If I bind it to a Enumerable<Task> directly it seems to not occur. 

<telerik:RadGridView CanUserReorderColumns="False" RowIndicatorVisibility="Collapsed" ScrollViewer.VerticalScrollBarVisibility="Auto"
                                ScrollViewer.HorizontalScrollBarVisibility="Auto" FrozenColumnCount="1" Margin="10" Grid.Row="1" ShowGroupPanel="False"
                                ItemsSource="{Binding MyViewModels}" SelectedItem="{Binding SelectedTask, Mode=TwoWay}"  AutoGenerateColumns="False">

           <telerik:RadGridView.Columns>
               <telerik:GridViewDataColumn UniqueName="ProductCode" DataMemberBinding="{Binding Task.ProductCode}" Header="Task (Product Code)" IsGroupable="False"/>
           </telerik:RadGridView.Columns>
</telerik:RadGridView>

My TaskViewModel look like this:

public class MyViewModel: ViewModelBase
{
    public MyViewModel(MyParentViewModel parentViewModel, TaskEntity task)
    {
        ParentViewModel = parentViewModel;
        Task = task;
    }

    public MyParentViewModel ParentViewModel { get; private set; }
    public TaskEntity Task { get; private set; }
}

[Ivan Ivanov]

Hello John,

Unfortunately, I have met some obstacles, while trying to reproduce your issue, having only the information, you have provided. Would you please, sign up for a registered trial license, so you can send us a demo project, reproducing the described issue ?


Sincerely,
Ivan Ivanov
the Telerik team

[John]

Hi there! I manage to find a solution for this after quite some time. The reason was this:

Where I create my ViewModel the code was looking like this:

public IList<MyViewModel> MyViewModels
{
    get {

        if(Tasks == null)
            return null;

        return Tasks.Select(p => new MyViewModel(this, p));
    }
}

However, when I changed it to look like this it solved all my issues:

public IList<MyViewModel> MyViewModels
{
    get {

        if(Tasks == null)
            return null;

        return Tasks.Select(p => new MyViewModel(this, p)).ToList();
    }
}

I didn't use the ToList, which seems to be the cause of the whole issue. Sorry for taking up your time.