在Windows Phone 8.1上阅读pdf时无法添加翻页图像

Question

I made an application on windows phone 8.1 for reading pdf using xfinium. I have problems when adding flipview upon reading the pdf. Image is not displayed and display an error message such as this link

Code:

async private void LoadFile(string name)
        {
            StorageFolder installedLocation = ApplicationData.Current.LocalFolder;
            StorageFolder koleksibuku = await installedLocation.CreateFolderAsync("koleksibuku", CreationCollisionOption.OpenIfExists);
            IReadOnlyList<StorageFile> files = await koleksibuku.GetFilesAsync();
            StorageFolder thumbfolder = await installedLocation.CreateFolderAsync("thumb", CreationCollisionOption.OpenIfExists);
            foreach (StorageFile file in files)
            {
                if (file.DisplayName == name)
                {
                    var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
                    Stream fileStream = stream.AsStreamForRead();

                    PdfFixedDocument document = new PdfFixedDocument(fileStream);
                    //fileStream.Dispose();
                    (Application.Current as App).Document = document;

                    int i = 0;



                    for (i = 0; i < document.Pages.Count; i++)
                    {
                        int index = i;

                        var t = Task<PdfBgraByteRenderingSurface>.Factory.StartNew(() =>
                        {
                            PdfPageRenderer renderer = new PdfPageRenderer(document.Pages[index]);
                            PdfBgraByteRenderingSurface rs = renderer.CreateRenderingSurface<PdfBgraByteRenderingSurface>(96, 96);
                            PdfRendererSettings settings = new PdfRendererSettings(thumbnailDpi, thumbnailDpi, rs);
                            renderer.ConvertPageToImage(settings);

                            return rs;
                        })
                            .ContinueWith(value =>
                            {

                                PdfBgraByteRenderingSurface rs = value.Result;
                                WriteableBitmap pageBitmap = new WriteableBitmap(rs.Width, rs.Height);
                                Stream imageStream = pageBitmap.PixelBuffer.AsStream();
                                imageStream.Write(rs.Bitmap, 0, rs.Bitmap.Length);

                                flipView.SelectionChanged += flipView_SelectionChanged;
                                flipView.Loaded += flipView_Loaded;
                                flipView.ItemsSource = pageBitmap;


                            }, TaskScheduler.FromCurrentSynchronizationContext());
                    }
                }

            }
        }

How to handle it?

Answer 1

My recommendation is to check the Length of the imageStream and its Position. The Position should be 0 and the imageStream.Length should be equal to rs.Bitmap.Length. If they are different please send a sample project to XFINIUM.PDF support.
Disclaimer: I work for the company that develops XFINIUM.PDF library.