dotnet/wpf · error · InvalidOperationException

SR.ListView_NotAllowShareColumnToTwoColumnCollection

Error message

SR.ListView_NotAllowShareColumnToTwoColumnCollection

What it means

WPF throws this InvalidOperationException when the same GridViewColumn instance is inserted into a GridViewColumnCollection while it already belongs to one. Each column tracks its ActualIndex (>=0 once parented), and a column cannot be shared by two collections. It protects the invariant that a column has exactly one owning collection.

Solutions

Remove the column from its current collection (or clone it) before inserting into the new collection
Create a new GridViewColumn instance per collection instead of sharing instances
If reusing layout, copy properties (Header, DisplayMemberBinding, Width) into fresh columns

Example fix

// before
foreach (var col in sharedColumns) { otherView.Columns.Add(col); }
// after
foreach (var col in sharedColumns) { otherView.Columns.Add(CloneColumn(col)); } // clone, don't share

Defensive patterns

Strategy: validation

Validate before calling

if (column.ActualIndex >= 0) throw new InvalidOperationException("Column already belongs to a collection; remove or clone it first.");

Type guard

bool CanInsert(GridViewColumn c) => c is null || c.ActualIndex < 0;

Try / catch

try { collection.Insert(idx, column); } catch (InvalidOperationException ex) when (ex.Message.Contains("column")) { /* handle shared column */ }

Prevention

Never store GridViewColumn instances in shared statics or resources used by multiple views
Clone columns when reusing layout across views
Remove a column from its current collection before moving it

When it happens

Trigger: Calling columnCollection.Insert/Add/Move (via InsertPreprocess -> ValidateColumnForInsert) with a GridViewColumn whose ActualIndex >= 0, i.e. a column that is already a member of another (or the same) GridViewColumnCollection.

Common situations: Reusing a single column array/field to populate two GridViews or ListViews; moving a column from one ListView to another without removing it first; sharing columns defined in XAML resources across multiple views.

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/42301eb653c008ab. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Controls/GridViewColumnCollection.cs:431

            }

            return null;
        }

        private void VerifyIndexInRange(int index, [CallerArgumentExpression(nameof(index))] string indexName = null)
        {
            ArgumentOutOfRangeException.ThrowIfNegative(index, indexName);
            ArgumentOutOfRangeException.ThrowIfGreaterThanOrEqual(index, _actualIndices.Count, indexName);
        }

        // Throw if column is null or already existed in a GVCC
        private void ValidateColumnForInsert(GridViewColumn column)
        {
            ArgumentNullException.ThrowIfNull(column);

            if (column.ActualIndex >= 0)
            {
                throw new InvalidOperationException(SR.ListView_NotAllowShareColumnToTwoColumnCollection);
            }
        }

        private void VerifyAccess()
        {
            if (IsImmutable)
            {
                throw new InvalidOperationException(SR.ListView_GridViewColumnCollectionIsReadOnly);
            }

            // Although CheckReentrancy() is called in base class, we still need to call it here again,
            // otherwise, when Reentrancy is found and exception is thrown, our operation is done and can't be undo.
            CheckReentrancy();
        }

        #endregion

        //------------------------------------------------------

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