dotnet/wpf · error · ArgumentException

SR.AnnotationServiceNotEnabled

Error message

SR.AnnotationServiceNotEnabled

What it means

AnnotationHelper.CheckInputs throws ArgumentException when the AnnotationService passed to a helper method (CreateHighlightForSelection, CreateTextStickyNoteForSelection, etc.) has not been enabled. The helper methods require an actively enabled service because they operate on the service's viewer and store. Calling a helper with a service that Enable() was never called on (or after Disable()) produces this error.

Solutions

  1. Call service.Enable(annotationStore) on the AnnotationService before invoking any AnnotationHelper method.
  2. Check service.IsEnabled prior to calling the helper and enable it if false.
  3. Ensure you are passing the same AnnotationService instance that was enabled for the viewer, not a newly constructed one.
  4. If the service was disabled (e.g. on page unload), re-enable it before further helper calls.

Example fix

// before
var service = new AnnotationService(fdvViewer);
AnnotationHelper.CreateHighlightForSelection(service, "me", "note", anchors, rects);

// after
var service = new AnnotationService(fdvViewer);
service.Enable(new XmlStreamStore(new Uri("annotations.xml")));
if (service.IsEnabled)
    AnnotationHelper.CreateHighlightForSelection(service, "me", "note", anchors, rects);
Defensive patterns

Strategy: validation

Validate before calling

if (service == null) throw new ArgumentNullException(nameof(service));
if (!service.IsEnabled)
    service.Enable(store); // enable before helper calls

Type guard

bool CanUseHelpers(AnnotationService s) => s != null && s.IsEnabled;

Try / catch

try { AnnotationHelper.CreateHighlightForSelection(service, ...); }
catch (ArgumentException ex) when (ex.Message.Contains(nameof(service))) { /* enable service and retry */ }

Prevention

When it happens

Trigger: Calling any public AnnotationHelper static method (e.g. AnnotationHelper.CreateHighlightForSelection(service, ...)) with an AnnotationService instance whose IsEnabled property is false, i.e. Enable() was never called or Disable() was called beforehand.

Common situations: Creating the AnnotationService and immediately calling AnnotationHelper without first calling service.Enable(store); calling helpers after service.Disable(); enabling the service asynchronously and calling a helper before Enable completes; using a different service instance than the one enabled for the viewer.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/f1d7e43a0d6e1b43. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Annotations/AnnotationHelper.cs:1084

            }

            annot.Anchors.Clear();
            annot.Anchors.Add(anchor);
        }

        /// <summary>
        ///     Common input checks.  Service must be non-null and enabled.
        /// </summary>
        /// <param name="service">service to check</param>
        /// <exception cref="ArgumentNullException">service is null</exception>
        /// <exception cref="ArgumentException">service is not enabled</exception>
        private static void CheckInputs(AnnotationService service)
        {
            ArgumentNullException.ThrowIfNull(service);

            if (!service.IsEnabled)
            {
                throw new ArgumentException(SR.AnnotationServiceNotEnabled, nameof(service));
            }

            DocumentViewerBase viewer = service.Root as DocumentViewerBase;
            if (viewer == null)
            {
                FlowDocumentScrollViewer scrollViewer = service.Root as FlowDocumentScrollViewer;
                FlowDocumentReader reader = service.Root as FlowDocumentReader;
                Invariant.Assert((scrollViewer != null) || (reader != null), "Service's Root must be either a FlowDocumentReader, DocumentViewerBase or a FlowDocumentScrollViewer.");
            }
            else
            {
                if (viewer.Document == null)
                {
                    throw new InvalidOperationException(SR.OnlyFlowFixedSupported);
                }
            }
        }

View on GitHub (pinned to 81131a70a4)