dotnet/wpf · error · InvalidOperationException

SR.Format(SR.MemberNotAllowedDuringTransaction…

Error message

SR.Format(SR.MemberNotAllowedDuringTransaction, "CancelNew", "EditItem")

What it means

ArgumentException from BindingListCollectionView.CancelNew: the edit-transaction API is being used in the wrong order — CancelNew is called while the open transaction is an EditItem transaction (not AddNew), and this member is not allowed during that transaction.

Solutions

Match cancel calls to the transaction type: call EndEdit/CancelEdit for EditItem, CancelNew only for AddNew
Check IsAddingNew before calling CancelNew

Example fix

// before
if (view.IsAddingNew) view.CancelNew();

// after
if (view.IsEditingItem) view.CancelEdit();
if (view.IsAddingNew) view.CancelNew();

Defensive patterns

Strategy: validation

Validate before calling

// C#
if (view.IsEditingItem) view.CancelEdit();
if (view.IsAddingNew) view.CancelNew();

Type guard

bool CanCancelNew(IEditableCollectionView v) => !v.IsEditingItem && v.IsAddingNew;

Try / catch

try { view.CancelNew(); }
catch (InvalidOperationException ex) { Log.Warn("CancelNew blocked by open EditItem transaction", ex); }

Prevention

Always cancel the edit transaction before canceling the add.
Use a single reset helper for cancel/cleanup paths.
Check state flags instead of assuming which transaction is open.

When it happens

Trigger: Calling EditItem() and then CancelNew() without closing the edit transaction via CommitEdit() or CancelEdit().

Common situations: A cancel button that calls both CancelEdit and CancelNew but in the wrong order; error-recovery code that resets add state while an item edit remains open; user hits Escape during a DataGrid edit that started from AddNew.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/0e3e8a7357d4bc4b. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Data/BindingListCollectionView.cs:696

            if (_newItem != NoNewItem)
            {
                int delta = (NewItemPlaceholderPosition == NewItemPlaceholderPosition.AtBeginning) ? 1 : 0;
                NotifyCollectionChangedEventArgs args = ProcessCommitNew(_newItemIndex, _newItemIndex + delta);
                if (args != null)
                {
                    base.OnCollectionChanged(InternalList, args);
                }
            }
        }

        /// <summary>
        /// Complete the transaction started by <seealso cref="AddNew"/>.  The new
        /// item is removed from the collection.
        /// </summary>
        public void CancelNew()
        {
            if (IsEditingItem)
                throw new InvalidOperationException(SR.Format(SR.MemberNotAllowedDuringTransaction, "CancelNew", "EditItem"));
            VerifyRefreshNotDeferred();

            if (_newItem == NoNewItem)
                return;

            // cancel the AddNew
            ICancelAddNew ican = InternalList as ICancelAddNew;
            IEditableObject ieo;

            BindingOperations.AccessCollection(InternalList,
                () =>
                {
                    ProcessPendingChanges();

                    if (ican != null)
                    {
                        ican.CancelNew(_newItemIndex);
                    }

View on GitHub (pinned to 81131a70a4)