DataGrid edition 'EditItem' is not allowed for this view` when bound to a WPF DataGrid

Question

I\'ve been reading about this at least for 4 hours, and seems to be the list type, but I have a situation:

A ObservableCollection that has a collection property.

Answer 1

Tks to @nit who give me the right path. Of course the problem reside on the base Type of EF collections

Hashet< T > And Datagrid need at least a List< T >, changing all my classes "those generated by Entity framework", give to me another problem, must make changes manually, and I have a lot of them.

My solution was to create a converter, that made the dirty work for me:

public class listToObservableCollection : BaseConverter, IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        HashSet<Level2> observableList = (HashSet<Level2>)value;
        return new ObservableCollection<Level2>(observableList);
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return (HashSet<Level2>)value;
    }
}

public abstract class BaseConverter : MarkupExtension
{
    public override object ProvideValue(IServiceProvider serviceProvider)
    {
        return this;
    }
}

And put it on the binding of my Datagrid2:

<!--part of my window definition--!>
xmlns:l="clr-namespace:Recursos;assembly=Recursos"
...
<!--part of my resources section--!>
<l:listToObservableCollection x:Key="listoToObservable"/>
...
<!--part of my datagrid definition--!>
ItemsSource="{Binding Level2,Converter={StaticResource listoToObservable}}"

The only thing on the air is how to make a generic converter, but for now it works fine.

Answer 2

Here is a generic Converter that I used

public class ObservableCollectionConverter: IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var observableType= typeof (ObservableCollection<>).MakeGenericType(value.GetType().GetGenericArguments());
        return Activator.CreateInstance(observableType, value);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var observableType = typeof(HashSet<>).MakeGenericType(value.GetType().GetGenericArguments());
        return Activator.CreateInstance(observableType, value);
    }
}

Answer 3

You might try this. Attach a BeginningEdit handler to your DataGrid and point to this code:

    private void Grid_BeginningEdit(object sender, DataGridBeginningEditEventArgs e)
    {
        //// Have to do this in the unusual case where the border of the cell gets selected.
        //// and causes a crash 'EditItem is not allowed'
        e.Cancel = true;
    }

This will only hit if you somehow manage to physically tap down on the border of the cell. The event's OriginalSource is a Border, and I think what may happen here is, instead of a TextBox or other editable element being the source as expected, this un-editable Border comes through for editing, which causes an exception that is buried in the 'EditItem is not allowed' exception. Canceling this RoutedEvent before it can bubble on through with its invalid OriginalSource stops that error occurring in its tracks.

Answer 4

you can set IsReadOnly property. maybe Exception not occur... try it in xaml file..

IsReadOnly="True"

Answer 5

I resolved this putting my datagrid in readonly mode

<DataGrid 
                Name="dtgBulkInsert"
                CanUserSortColumns="True" 
                Height="300" Visibility="Collapsed" IsReadOnly="True">

....

Answer 6

I also solved this problem by using IsReadOnly="True".