/// <summary>
/// Shows the image.
/// </summary>
/// <param name="page">The page.</param>
/// <param name="imageBounds">The image bounds.</param>
/// <param name="imageUri">The image URI.</param>
/// <param name="backgroundColor">Color of the background.</param>
private static async void ShowImage(Page page, Rect imageBounds, Uri imageUri, Color backgroundColor)
{
var compositor = ElementCompositionPreview.GetElementVisual(page).Compositor;
var windowSize = new Vector2((float)Window.Current.Bounds.Width, (float)Window.Current.Bounds.Height);
//
// Create a container visual to hold the color fill background and image visuals.
// Configure this visual to scale from the center.
//
var container = compositor.CreateContainerVisual();
container.Size = windowSize;
container.CenterPoint = new Vector3(windowSize.X, windowSize.Y, 0) * .5f;
ElementCompositionPreview.SetElementChildVisual(page, container);
//
// Create the colorfill sprite for the background, set the color to the same as app theme
//
var backgroundSprite = compositor.CreateSpriteVisual();
backgroundSprite.Size = windowSize;
backgroundSprite.Brush = compositor.CreateColorBrush(backgroundColor);
container.Children.InsertAtBottom(backgroundSprite);
//
// Create the image sprite containing the splash screen image. Size and position this to
// exactly cover the Splash screen image so it will be a seamless transition between the two
//
var surface = await SurfaceLoader.LoadFromUri(imageUri);
var imageSprite = compositor.CreateSpriteVisual();
imageSprite.Brush = compositor.CreateSurfaceBrush(surface);
imageSprite.Offset = new Vector3((float)imageBounds.X, (float)imageBounds.Y, 0f);
imageSprite.Size = new Vector2((float)imageBounds.Width, (float)imageBounds.Height);
container.Children.InsertAtTop(imageSprite);
}
private async void LoadSurface()
{
// If we're clearing out the content, return
if (_uri == null)
{
ReleaseSurface();
return;
}
try
{
// Start a timer to enable the placeholder image if requested
if (_surface == null && _placeholderDelay >= TimeSpan.Zero)
{
_timer = new DispatcherTimer();
_timer.Interval = _placeholderDelay;
_timer.Tick += Timer_Tick;
_timer.Start();
}
// Load the image asynchronously
CompositionDrawingSurface surface = await SurfaceLoader.LoadFromUri(_uri, Size.Empty, _loadEffectDelegate);
if (_surface != null)
{
ReleaseSurface();
}
_surface = surface;
// The surface has changed, so we need to re-measure with the new surface dimensions
InvalidateMeasure();
// Async operations may take a while. If we've unloaded, return now.
if (_unloaded)
{
ReleaseSurface();
return;
}
// Update the brush
UpdateBrush();
// Success, fire the Opened event
if (ImageOpened != null)
{
ImageOpened(this, null);
}
//
// If we created the loading placeholder, now that the image has loaded
// cross-fade it out.
//
if (_sprite != null && _sprite.Children.Count > 0)
{
Debug.Assert(_timer == null);
StartCrossFade();
}
else if (_timer != null)
{
// We didn't end up loading the placeholder, so just stop the timer
_timer.Stop();
_timer = null;
}
}
catch (FileNotFoundException)
{
if (ImageFailed != null)
{
ImageFailed(this, null);
}
}
}
