private async Task LoadImages(ImageLoader imageLoader)
{
// only load images when we are connected
if (InternetConnectivity.IsConnected())
{
// create Flickr reader
var reader = new FlickrReader("unicorn");
//load Flickr images
var images = await reader.GetImages();
// store images to database
await imageLoader.StoreImages(images);
}
}
public MainPage()
{
this.InitializeComponent();
var imageLoader = new ImageLoader();
// start image loading task, don't wait
var task = ThreadPool.RunAsync(async (source) =>
{
await LoadImages(imageLoader);
});
// schedule image databaase refresh every 20 seconds
TimeSpan imageLoadPeriod = TimeSpan.FromSeconds(20);
ThreadPoolTimer imageLoadTimes = ThreadPoolTimer.CreatePeriodicTimer(
async (source) =>
{
await LoadImages(imageLoader);
}, imageLoadPeriod);
TimeSpan displayImagesPeriod = TimeSpan.FromSeconds(5);
// display new images every five seconds
ThreadPoolTimer imageDisplayTimer = ThreadPoolTimer.CreatePeriodicTimer(
async (source) =>
{
// get next image (byte aray) from database
var imageBytes = imageLoader.GetNextImage();
if (imageBytes != null)
{
// we have to update UI in UI thread only
await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
async () =>
{
// create bitmap from byte array
BitmapImage bitmap = new BitmapImage();
MemoryStream ms = new MemoryStream(imageBytes);
await bitmap.SetSourceAsync(ms.AsRandomAccessStream());
// display image
splashImage.Source = bitmap;
}
);
}
}, displayImagesPeriod);
}
