I use InkCanvas in my UWP application that I developed as a Windows 10 App. I am successfully saving the drawing in JPG format to LocalStorage.

I want to load the drawing into the InkCanvas object so that it can be selected and rearranged over the DataGrid. I am encountering the following error.

Thank you so much if you help.

Exception:

{System.Runtime.InteropServices.COMException (0x80004005): Error HRESULT E_FAIL has been returned from a call to a COM component. at Windows.UI.Input.Inking.InkStrokeContainer.LoadAsync(IInputStream inputStream) at TICAppUWP.CoverPage.canvasFileNotes()}

Save:

StorageFolder storageFolder = await StorageFolder.GetFolderFromPathAsync(fileNotesFolderPath);

            string fileName = App._PreparedFor  "_"  App._Date   "_PageID_"   App._CoverPageID;
            var file = await storageFolder.CreateFileAsync(fileName   ".jpg", CreationCollisionOption.ReplaceExisting);

            CanvasDevice device = CanvasDevice.GetSharedDevice();
            CanvasRenderTarget renderTarget = new CanvasRenderTarget(device, (int)myInkCanvas.ActualWidth, (int)myInkCanvas.ActualHeight, 96);

            using (var ds = renderTarget.CreateDrawingSession())
            {
                ds.Clear(Windows.UI.Colors.White);
                ds.DrawInk(myInkCanvas.InkPresenter.StrokeContainer.GetStrokes());
            }

            using (var fileStream = await file.OpenAsync(FileAccessMode.ReadWrite))
            {
                await renderTarget.SaveAsync(fileStream, CanvasBitmapFileFormat.Jpeg, 1f);
            }

Load:

StorageFolder storageFolder = await StorageFolder.GetFolderFromPathAsync(fileNotesFolderPath);
            string fileName = App._PreparedFor   "_"   App._Date   "_PageID_"   App._CoverPageID;
            var file = await storageFolder.GetFileAsync(fileName   ".jpg");

            StorageFile inkFile = await storageFolder.GetFileAsync(fileName   ".jpg");

            if (file != null)
            {
                Windows.Storage.Streams.IRandomAccessStream stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);

                using (var inputStream = stream.GetInputStreamAt(0))
                {
                    await myInkCanvas.InkPresenter.StrokeContainer.LoadAsync(stream);
                }

                stream.Dispose();
            }

CodePudding user response：

UWP (Windows 10 App) InkCanvas LoadAsync Error HRESULT E_FAIL has been returned from a call to a COM component

Please refer to InkStrokeContainer document Asynchronously loads all InkStroke objects from the specified stream to the InkStroke collection that is managed by the InkStrokeContainer.

But you passed stream to LoadAsync method is image file stream but not InkStroke collection stream. so it will throw exception.

For this scenario, you need save InkStroke stream with SaveAsync method, but not save as image file.