属性动画的使用

Android提供了两个类来实现属性动画:ObjectAnimator和ValueAnimator

ObjectAnimator

1.单个动画效果:

ObjectAnimator
.ofFloat(view,"rotation",0.0F,180F)
.setDuration(500)
.start();
//rotationX 绕x轴旋转
//rotation 绕中心旋转

提供了ofInt、ofFloat、ofObject，这几个方法都是设置动画作用的元素、作用的属性、动画开始、结束、以及中间的任意个属性值。

当对于属性值，只设置一个的时候，会认为当然对象该属性的值为开始（getPropName反射获取），然后设置的值为终点。如果设置两个，则一个为开始、一个为结束~~~

2.多种动画效果重叠

PropertyValuesHolder pvhX = PropertyValuesHolder.ofFloat("alpha", 1f,
0f, 1f);
PropertyValuesHolder pvhY = PropertyValuesHolder.ofFloat("scaleX", 1f,
0, 1f);
PropertyValuesHolder pvhZ = PropertyValuesHolder.ofFloat("scaleY", 1f,
0, 1f);
ObjectAnimator.ofPropertyValuesHolder(view, pvhX, pvhY,pvhZ).setDuration(1000).start();

ValueAnimation

valueAnimation比ObjectAnimation使用方法类似

int height = getWindowManager().getDefaultDisplay().getHeight();
int view_height = view.getHeight();
ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, height/2 - view_height);
valueAnimator
.setDuration(500)
.setTarget(view);
valueAnimator.start();

valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
view.setTranslationY((Float) animation.getAnimatedValue());
}
});

动画时间的监听

valueAnimator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {
//开始
}

@Override
public void onAnimationEnd(Animator animation) {
//结束
}

@Override
public void onAnimationCancel(Animator animation) {
// 取消
}

@Override
public void onAnimationRepeat(Animator animation) {
//重复
}
});

如果只要监听一种事件可以创建AnimatorListener的适配器对象AnimatorListenerAdapter

valueAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
}
});

valueAnimator还有cancel()和end()方法：cancel动画立即停止，停在当前的位置；end动画直接到最终状态。

AnimatorSet

同时执行动画

ObjectAnimator anim1 = ObjectAnimator.ofFloat(view, "scaleX",
1.0f, 2f);
ObjectAnimator anim2 = ObjectAnimator.ofFloat(view, "scaleY",
1.0f, 2f);
AnimatorSet animSet = new AnimatorSet();
animSet.setDuration(2000);
animSet.setInterpolator(new LinearInterpolator());
//两个动画同时执行
animSet.playTogether(anim1, anim2);
animSet.start();

按顺序执行动画

float cx = view.getX();
ObjectAnimator anim1 = ObjectAnimator.ofFloat(view, "scaleX",
1.0f, 2f);
ObjectAnimator anim2 = ObjectAnimator.ofFloat(view, "scaleY",
1.0f, 2f);
ObjectAnimator anim3 = ObjectAnimator.ofFloat(view,
"x",  cx ,  0f);
ObjectAnimator anim4 = ObjectAnimator.ofFloat(view,
"x", cx);

/**
* anim1，anim2,anim3同时执行
* anim4接着执行
*/
AnimatorSet animSet = new AnimatorSet();
animSet.play(anim1).with(anim2);
animSet.play(anim2).with(anim3);
animSet.play(anim4).after(anim3);
animSet.setD
4000
uration(1000);
animSet.start();