★19.动画

补间动画

动画类型

• AlphaAnimation
• ScaleAnimation
• TranslateAnimation
• RotateAnimation
• AnimationSet：动画集合

插入器

• AccelerateInterpolator：加速
• DecelerateInterpolator：减速
• AccelerateDecelerateInterpolator：加速，减速
• BounceInterpolator：弹跳
• CycleInterpolator：循环
• LinearInterpolator：线性
• AnticipateInterpolator：反向
• OvershootInterpolator：超越，恢复
• AnticipateOvershootInterpolator：反向，超越，恢复

代码示例

Animation alphaAnimation = new AlphaAnimation(1.0f, 0.1f);
alphaAnimation.setDuration(1000);
alphaAnimation.setAnimationListener(new AnimatorListenerAdapter() {
    @Override
    public void onAnimationStart(Animation animation) {
        // 开始动画
    }
    @Override
    public void onAnimationEnd(Animation animation) {
        // 结束动画
    }
    @Override
    public void onAnimationRepeat(Animation animation) {
        // 开始重复动画
    }
});
alphaAnimation.setFillAfter(true); //动画结束后不恢复原状
tempview.startAnimation(alphaAnimation);

Animation animation = new TranslateAnimation(0f, 30f, 0f, 30f);
animation.setDuration(1000);
animation.setFillAfter(true); //动画结束后不恢复原状
AnimationSet set = new AnimationSet(false);
set.addAnimation(animation);
set.addAnimation(animation);
view.startAnimation(set);

XML示例

Animation alphaAnimation = AnimationUtils.loadAnimation(this, R.anim.aaaa);
view.startAnimation(alphaAnimation);

帧动画

XML格式

代码播放动画

ImageView tempview = (ImageView) findViewById(R.id.tempview);
tempview.setImageResource(R.drawable.click_loving_anim_1);
AnimationDrawable animation = (AnimationDrawable) tempview.getDrawable();
animation.start();

注意事项

• 帧动画 XML 文件应该放在 drawable 文件夹。

属性动画

ObjectAnimator

简介

• ObjectAnimator可用于实现简单属性动画。

简单示例

方式一

ObjectAnimator.ofFloat(view, "RotationX", 0.0f, 360.0f).setDuration(1000).start();

方式二

view.setAlpha(0f);
view.animate().setDuration(1000).alpha(1f);

复杂

ObjectAnimator animator = ObjectAnimator.ofFloat(view, "XXX", 0.0F, 1.0F).setDuration(1500);
animator.addUpdateListener(animation -> {
    float cVal = (Float) animation.getAnimatedValue();
    view.setScaleX(cVal);
    view.setScaleY(cVal);
});
animator.setInterpolator(new LinearInterpolator());
animator.addListener(new AnimatorListenerAdapter() {
    @Override
    public void onAnimationStart(Animator animation) {
        // 开始动画时
    }
    @Override
    public void onAnimationEnd(Animator animation) {
        // 结束动画时
    }
    @Override
    public void onAnimationCancel(Animator animation) {
        // 取消动画时
    }
    @Override
    public void onAnimationRepeat(Animator animation) {
        // 动画重新开始时
    }
});
animator.start();

XML方式

Animator anim = AnimatorInflater.loadAnimator(this, R.animator.abc);
anim.setTarget(view);
anim.start();

PropertyValuesHolder

简介

• PropertyValuesHolder用于拼接多个动画。

简单示例

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

ValueAnimator

简介

• ValueAnimator进行复杂属性动画定义。

简单示例

ValueAnimator valueAnimator = new ValueAnimator();
valueAnimator.setObjectValues(new PointF(0, 0), new PointF(0, 0));
valueAnimator.setDuration(3000);
valueAnimator.setInterpolator(new LinearInterpolator());
valueAnimator.setEvaluator(new TypeEvaluator() {
    @Override
    public PointF evaluate(float fraction, PointF startValue, PointF endValue) {
        // fraction与进度有关，在0-1之间
        // 根据三个参数来计算出返回值
        return new PointF();
    }
});
valueAnimator.addUpdateListener(animation -> {
    PointF point = (PointF) animation.getAnimatedValue();
    view.setX(point.x);
    view.setY(point.y);
});
valueAnimator.start();

AnimatorSet

简介

• AnimatorSet用于控制多个属性动画的行为。

简单示例

ObjectAnimator anim1 = ObjectAnimator.ofFloat(view, "scaleX", 1.0f, 2f).setDuration(1000);
ObjectAnimator anim2 = ObjectAnimator.ofFloat(view, "scaleY", 1.0f, 2f).setDuration(1000);
AnimatorSet animatorSet = new AnimatorSet();
animatorSet.playSequentially(anim1, anim2);
animatorSet.playTogether(anim1, anim2);
animatorSet.play(anim1).before(anim2);
animatorSet.play(anim1).with(anim2);
animatorSet.play(anim1).after(anim2);
animatorSet.start();

布局动画

简介

• 配合RecycleView使用。

简单示例

mTransition = new LayoutTransition();
mTransition.setAnimator(LayoutTransition.APPEARING, ObjectAnimator.ofFloat(null, "scaleX", 0f, 1f));
mTransition.setAnimator(LayoutTransition.CHANGE_APPEARING,mTransition.getAnimator(LayoutTransition.CHANGE_APPEARING));
mTransition.setAnimator(LayoutTransition.DISAPPEARING, mTransition.getAnimator(LayoutTransition.DISAPPEARING));
mTransition.setAnimator(LayoutTransition.CHANGE_DISAPPEARING,mTransition.getAnimator(LayoutTransition.CHANGE_DISAPPEARING));
mGridLayout.setLayoutTransition(mTransition);