dotnet/wpf · error · InvalidOperationException

throw new…

Error message

throw new InvalidOperationException(SR.Format(SR.MemberNotAllowedForView, "EditItem"));

What it means

CollectionViewProxy.EditItem(item) starts an edit transaction on the proxied view via IEditableCollectionView. When the wrapped view does not implement that interface (null `ecv` at CollectionViewProxy.cs:603), the proxy throws InvalidOperationException: editing is not allowed for this view.

Solutions

1. Check CanEditItem (or cast ProxiedView as IEditableCollectionView) before calling EditItem
2. Edit the data object directly and raise PropertyChanged instead of using view-level edit transactions
3. Use a source collection whose view implements IEditableCollectionView

Example fix

// before
proxy.EditItem(currentItem);
// after
if (proxy.CanEditItem)
{
    proxy.EditItem(currentItem);
}

if (!proxy.CanEditItem) return;
proxy.EditItem(item);

bool SupportsEditItem(CollectionViewProxy p) => p?.ProxiedView is IEditableCollectionView;

try { proxy.EditItem(item); }
catch (InvalidOperationException ex) when (ex.Message.Contains("EditItem")) { /* edit object directly instead */ }

When it happens

Trigger: Calling EditItem on a CollectionViewProxy whose ProxiedView is not an IEditableCollectionView (e.g. custom views, views over non-editable sources).

Common situations: Programmatic cell-edit commits in data grids bound to unsupported collections; data-binding infrastructure invoking EditItem automatically; view code ported between collection types.

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

• throw new…
• throw new…
• throw new…
• throw new…
• throw new…

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/fbb0d89a722a18e8. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/MS/Internal/Data/CollectionViewProxy.cs:603

        #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 = ProxiedView 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 = ProxiedView as IEditableCollectionView;
            if (ecv != null)
            {
                ecv.CommitEdit();
            }
            else
            {
                throw new InvalidOperationException(SR.Format(SR.MemberNotAllowedForView, "CommitEdit"));
            }

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