private async Task Open(CanvasVirtualBitmapOptions options) { var filePicker = new FileOpenPicker(); filePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary; filePicker.FileTypeFilter.Add("*"); var file = await filePicker.PickSingleFileAsync(); if (file == null) { return; } if (imageStream != null) { imageStream.Dispose(); imageStream = null; } try { imageStream = new ByteCounterStreamProxy(await file.OpenReadAsync()); virtualBitmapOptions = options; IOGraph.Invalidate(); await LoadVirtualBitmap(); } catch { var message = string.Format("Error opening '{0}'", file.Name); var messageBox = new MessageDialog(message, "Virtual Bitmap Example").ShowAsync(); } }