在安卓中有四种类型的动画 - 旋转、透明度、缩放和位移。我想准备一种曲线位移动画,这个可行吗?
View view;
animator = ValueAnimator.ofFloat(0, 1); // values from 0 to 1
animator.setDuration(5000); // 5 seconds duration from 0 to 1
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener()
{
@Override
public void onAnimationUpdate(ValueAnimator animation) {
float value = ((Float) (animation.getAnimatedValue()))
.floatValue();
// Set translation of your view here. Position can be calculated
// out of value. This code should move the view in a half circle.
view.setTranslationX((float)(200.0 * Math.sin(value*Math.PI)));
view.setTranslationY((float)(200.0 * Math.cos(value*Math.PI)));
}
});
希望它能正常工作。我只是从我的一个应用程序中复制并粘贴了代码(并进行了缩短和更改)。
这里是我使用的动画制作工具:
目的:在路径“path”上移动视图“view”
适用于Android v21+版本:
// Animates view changing x, y along path co-ordinates
ValueAnimator pathAnimator = ObjectAnimator.ofFloat(view, "x", "y", path)
Android v11+:
// Animates a float value from 0 to 1
ValueAnimator pathAnimator = ValueAnimator.ofFloat(0.0f, 1.0f);
// This listener onAnimationUpdate will be called during every step in the animation
// Gets called every millisecond in my observation
pathAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
float[] point = new float[2];
@Override
public void onAnimationUpdate(ValueAnimator animation) {
// Gets the animated float fraction
float val = animation.getAnimatedFraction();
// Gets the point at the fractional path length
PathMeasure pathMeasure = new PathMeasure(path, true);
pathMeasure.getPosTan(pathMeasure.getLength() * val, point, null);
// Sets view location to the above point
view.setX(point[0]);
view.setY(point[1]);
}
});
与之类似:Android如何使位图沿着路径移动?
pathMeasure.getLength()/2
,因为视图总是返回到它的原始位置。 - Rick