public void Selected(SpriteVisual hostVisual)
{
// Set ColorBrush as Source to NineGridBrush with HollowCenter and insert child Content visual
hostVisual.Brush = _nineGridBrush;
hostVisual.Children.InsertAtTop(_borderedContent);
// Run expression animations to manage the size of borderedContent child visual
var hostNode = hostVisual.GetReference();
var nineBrush = _nineGridBrush.GetReference();
var xSizeExpression = hostNode.Size.X - (nineBrush.LeftInset * nineBrush.LeftInsetScale + nineBrush.RightInset * nineBrush.RightInsetScale);
var ySizeExpression = hostNode.Size.Y - (nineBrush.TopInset * nineBrush.TopInsetScale + nineBrush.BottomInset + nineBrush.BottomInsetScale);
var xOffsetExpression = nineBrush.LeftInset * nineBrush.LeftInsetScale;
var yOffsetExpression = nineBrush.TopInset * nineBrush.TopInsetScale;
_borderedContent.StartAnimation("Size.X", xSizeExpression);
_borderedContent.StartAnimation("Size.Y", ySizeExpression);
_borderedContent.StartAnimation("Offset.X", xOffsetExpression);
_borderedContent.StartAnimation("Offset.Y", yOffsetExpression);
}
private void SamplePage_Loaded(object sender, Windows.UI.Xaml.RoutedEventArgs e)
{
Compositor compositor = ElementCompositionPreview.GetElementVisual(MyGrid).Compositor;
ContainerVisual container = compositor.CreateContainerVisual();
ElementCompositionPreview.SetElementChildVisual(MyGrid, container);
//
// Create a couple of SurfaceBrushes for the orbiters and center
//
_redBallSurface = ImageLoader.Instance.LoadFromUri(new Uri("ms-appx:///Samples/SDK 10586/PropertySets/RedBall.png"));
_blueBallSurface = ImageLoader.Instance.LoadFromUri(new Uri("ms-appx:///Samples/SDK 10586/PropertySets/BlueBall.png"));
//
// Create the center and orbiting sprites
//
SpriteVisual redSprite = compositor.CreateSpriteVisual();
redSprite.Brush = _redBallSurface.Brush;
redSprite.Size = new Vector2(100f, 100f);
redSprite.Offset = new Vector3((float)Window.Current.Bounds.Width / 2 - redSprite.Size.X / 2, 150f, 0f);
container.Children.InsertAtTop(redSprite);
SpriteVisual blueSprite = compositor.CreateSpriteVisual();
blueSprite.Brush = _blueBallSurface.Brush;
blueSprite.Size = new Vector2(25f, 25f);
blueSprite.Offset = new Vector3((float)Window.Current.Bounds.Width / 2 - redSprite.Size.X / 2, 50f, 0f);
container.Children.InsertAtTop(blueSprite);
//
// Create the PropertySet that contains all the value referenced in the expression. We can also
// animate these properties, leading to the expression being re-evaluated per frame.
//
_propertySet = compositor.CreatePropertySet();
_propertySet.InsertScalar("Rotation", 0f);
_propertySet.InsertVector3("CenterPointOffset", new Vector3(redSprite.Size.X / 2 - blueSprite.Size.X / 2,
redSprite.Size.Y / 2 - blueSprite.Size.Y / 2,
0));
//
// Create the expression. This expression positions the orbiting sprite relative to the center of
// of the red sprite's center. As we animate the red sprite's position, the expression will read
// the current value of it's offset and keep the blue sprite locked in orbit.
//
var propSetCenterPoint = _propertySet.GetReference().GetVector3Property("CenterPointOffset");
var propSetRotation = _propertySet.GetReference().GetScalarProperty("Rotation");
var orbitExpression = redSprite.GetReference().Offset + propSetCenterPoint +
EF.Vector3(
EF.Cos(EF.ToRadians(propSetRotation)) * 150,
EF.Sin(EF.ToRadians(propSetRotation)) * 75,
0);
// Start the expression animation!
blueSprite.StartAnimation("Offset", orbitExpression);
// Now animate the rotation property in the property bag, this generates the orbitting motion.
var linear = compositor.CreateLinearEasingFunction();
var rotAnimation = compositor.CreateScalarKeyFrameAnimation();
rotAnimation.InsertKeyFrame(1.0f, 360f, linear);
rotAnimation.Duration = TimeSpan.FromMilliseconds(4000);
rotAnimation.IterationBehavior = AnimationIterationBehavior.Forever;
_propertySet.StartAnimation("Rotation", rotAnimation);
// Lastly, animation the Offset of the red sprite to see the expression track appropriately
var offsetAnimation = compositor.CreateScalarKeyFrameAnimation();
offsetAnimation.InsertKeyFrame(0f, 50f);
offsetAnimation.InsertKeyFrame(.5f, 150f);
offsetAnimation.InsertKeyFrame(1f, 50f);
offsetAnimation.Duration = TimeSpan.FromMilliseconds(4000);
offsetAnimation.IterationBehavior = AnimationIterationBehavior.Forever;
redSprite.StartAnimation("Offset.Y", offsetAnimation);
}