public async Task <InkStrokeContainer> LoadInking(int pageNumber)
{
// Load inking from Ink Dictionary if exist
InkStrokeContainer inkStrokeContainer;
if (!inkDictionary.TryGetValue(pageNumber, out inkStrokeContainer))
{
// Try to load inking from app data folder if inking not found in Ink Dictionary.
// A new ink stroke container will be returned if no inking found.
inkStrokeContainer = await inAppInking.LoadInking(pageNumber);
// Load in-file ink strokes
List <InkStroke> inPageStrokes = pdfModel.LoadInFileInkAnnotations(pageNumber);
// Check if any strokes has been deleted.
List <InkStroke> erasedStrokes = await inAppInking.LoadErasedStrokes(pageNumber);
// Remove erased strokes from in-file strokes.
List <InkStroke> remainingStrokes = SubstractInkStrokes(inPageStrokes, erasedStrokes.Select(item => item.Clone()).ToList());
inkStrokeContainer.AddStrokes(remainingStrokes);
inkDictionary[pageNumber] = inkStrokeContainer;
}
return(inkStrokeContainer);
}
