| -api-id | -api-type |
|---|---|
T:Windows.UI.Core.AnimationMetrics.OpacityAnimation |
winrt class |
Provides methods that enable you to retrieve the parameters of an opacity (fade in or fade out) animation.
The timing controls Control1 and Control2 specify the location of the first and second control points of a cubic Bézier curve. These two points have the same meaning as they do in the CSS transition-timing-function property. Control point zero is always (0,0) and control point three is always (1,1). The coordinates of Control1 and Control2 are always in the range 0 to 1, inclusive.
On the resulting Bézier curve, the x-coordinate represents time and the y-coordinate represents progress. The raw curve from (0,0) to (1,1) is scaled to match the actual duration and range of the animated transition, such that x=0 is the starting time of the transform, x=1 is the ending time, y=0 is the initial value of the animated property, and y=1 is the final value. Values of x and y between 0 and 1 represent corresponding intermediate values of time and the animation.
To obtain an instance of the OpacityAnimation class, you first obtain the collection of animations in the animation description, and then walk that array of animations to find any that are of type opacity. The following example shows this process. The effect and target parameters are assumed to have been previously assigned.
using Windows.UI.Core.AnimationMetrics;
AnimationDescription animationDescription = new AnimationDescription(effect, target);
foreach (var animation in animationDescription.Animations)
{
switch (animation.Type)
{
case PropertyAnimationType.Scale:
{
ScaleAnimation scale = animation as ScaleAnimation;
// Retrieve scale animation metrics.
}
break;
case PropertyAnimationType.Translation:
{
TranslationAnimation scale = animation as TranslationAnimation;
// Retrieve translation animation metrics.
}
break;
case PropertyAnimationType.Opacity:
{
OpacityAnimation opacity = animation as OpacityAnimation;
// Retrieve opacity animation metrics.
}
break;
}
}