dotnet/wpf · error · InvalidOperationException

SR.Format(SR.MemberNotAllowedForView, "EditItem")

Error message

SR.Format(SR.MemberNotAllowedForView, "EditItem")

What it means

ItemCollection.EditItem throws InvalidOperationException(SR.MemberNotAllowedForView, "EditItem") when the underlying view does not implement IEditableCollectionView, so transactional editing of an item is unavailable. The wrapper forwards only to editing-capable views.

Solutions

  1. Bind ItemsSource to a collection whose default view implements IEditableCollectionView.
  2. Guard with `items.CanEditItem` (or check the view) before starting an edit transaction.
  3. Mutate the item's properties directly and rely on INotifyPropertyChanged instead of view-based edit transactions.

Example fix

// before
items.EditItem(selectedItem);
// after
if (items.CanEditItem)
    items.EditItem(selectedItem);
else
    throw new InvalidOperationException("View does not support EditItem");
Defensive patterns

Strategy: validation

Validate before calling

if (items.CanEditItem)
    items.EditItem(item);

Type guard

static bool CanEdit(ItemCollection c) => c.CollectionView is IEditableCollectionView;

Try / catch

try { items.EditItem(item); }
catch (InvalidOperationException) { /* edit transactions unsupported; mutate item directly */ }

Prevention

When it happens

Trigger: Calling items.EditItem(item) when ItemsSource's view is not an IEditableCollectionView.

Common situations: Editable DataGrid scenarios where the ItemsSource is a plain collection without an editable view; rebinding ItemsSource to a type whose default view lacks IEditableCollectionView while editing logic still runs.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/b02cf787f1d3c42d. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Controls/ItemCollection.cs:1083

        #region Transactional editing of an item

        /// <summary>
        /// Begins an editing transaction on the given item.  The transaction is
        /// completed by calling either <seealso cref="IEditableCollectionView.CommitEdit"/> or
        /// <seealso cref="IEditableCollectionView.CancelEdit"/>.  Any changes made to the item during
        /// the transaction are considered "pending", provided that the view supports
        /// the notion of "pending changes" for the given item.
        /// </summary>
        void    IEditableCollectionView.EditItem(object item)
        {
            IEditableCollectionView ecv = _collectionView as IEditableCollectionView;
            if (ecv != null)
            {
                ecv.EditItem(item);
            }
            else
            {
                throw new InvalidOperationException(SR.Format(SR.MemberNotAllowedForView, "EditItem"));
            }
        }

        /// <summary>
        /// Complete the transaction started by <seealso cref="IEditableCollectionView.EditItem"/>.
        /// The pending changes (if any) to the item are committed.
        /// </summary>
        void    IEditableCollectionView.CommitEdit()
        {
            IEditableCollectionView ecv = _collectionView as IEditableCollectionView;
            if (ecv != null)
            {
                ecv.CommitEdit();
            }
            else
            {
                throw new InvalidOperationException(SR.Format(SR.MemberNotAllowedForView, "CommitEdit"));
            }

View on GitHub (pinned to 81131a70a4)