Android--属性动画基础

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/iv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@mipmap/ic_launcher"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        android:onClick="startAnimation"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

    public void startAnimation(View view) {
        ImageView iv = (ImageView) view;

        //注意第二个参数，只要view里面有setXXX()方法就可以通过反射达到变化的目的
        ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(iv, "translationX", 0f, 100f);
        objectAnimator.setDuration(500);
        objectAnimator.start();
    }

    public void startAnimation(View view) {
        final ImageView iv = (ImageView) view;

        //iv显然没有setXiaoming的方法,内部做了异常处理
        ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(iv, "xiaoming", 0f, 100f);
        objectAnimator.setDuration(500);
        objectAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                // 监听动画回调
                //animation.getAnimatedFraction();//动画执行的百分比 0~1 //API 12+
                float value = (float) animation.getAnimatedValue();//得到0f~100f当中的这个时间点对应的值
                iv.setScaleX(0.5f+value/200);
                iv.setScaleY(0.5f+value/200);
                //iv.setTranslationX(value);
            }
        });
        objectAnimator.start();
    }

    public void startAnimation(View view) {
        final ImageView iv = (ImageView) view;

        ValueAnimator animator = ValueAnimator.ofFloat(0f, 200f);
        animator.setDuration(200);
        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {

            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                float value = (float) animation.getAnimatedValue();//得到0f~100f当中的这个时间点对应的值
                iv.setScaleX(0.5f + value / 200);
                iv.setScaleY(0.5f + value / 200);
            }
        });
        animator.start();
    }

    public void startAnimation(View view) {
        final ImageView iv = (ImageView) view;

        PropertyValuesHolder holder1 = PropertyValuesHolder.ofFloat("alpha", 1f, 0.5f);
        PropertyValuesHolder holder2 = PropertyValuesHolder.ofFloat("scaleX", 1f, 0.5f);
        PropertyValuesHolder holder3 = PropertyValuesHolder.ofFloat("scaleY", 1f, 0.5f);
        ObjectAnimator animator = ObjectAnimator.ofPropertyValuesHolder(iv, holder1, holder2, holder3);
        animator.setDuration(200);
        animator.start();
    }

    public void startAnimation(View view) {
        final ImageView iv = (ImageView) view;

        ObjectAnimator animator1 = ObjectAnimator.ofFloat(iv, "translationX", 0f, 100f);
        ObjectAnimator animator2 = ObjectAnimator.ofFloat(iv, "alpha", 0f, 1f);
//      animator2.setStartDelay(startDelay)//设置延迟执行
        ObjectAnimator animator3 = ObjectAnimator.ofFloat(iv, "scaleX", 0f, 2f);
        AnimatorSet animatorSet = new AnimatorSet();
        animatorSet.setDuration(500);
//      animatorSet.play(animator3).with(animator2).after(animator1);//animator1在前面
//      animatorSet.play(animator3).with(animator2).before(animator1);//animator1在后面
//      animatorSet.playTogether(animator1,animator2,animator3);//同时执行
        animatorSet.playSequentially(animator1, animator2, animator3);//按顺序执行
        animatorSet.start();
    }

    public void startAnimation(View view) {
        final ImageView iv = (ImageView) view;

        ObjectAnimator objectAnimator = new ObjectAnimator();
        objectAnimator.setDuration(2000);
        objectAnimator.setObjectValues(new PointF(0, 0));
        final PointF pointF = new PointF();
        objectAnimator.setEvaluator(new TypeEvaluator() {
            @Override
            public Object evaluate(float fraction, Object startValue, Object endValue) {
                //估值计算方法---可以在执行的过程当中干预改变属性的值---做效果：用自己的算法来控制
                //不断地去计算修改坐标
                //x匀速运动 x=v*t 
                pointF.x = 400f * (fraction);
                //加速度 y=vt=1/2*g*t*t
                pointF.y = (float) (10f * 0.5f * 9.8f * Math.pow(fraction * 5, 2));
                return pointF;
            }
        });
        objectAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                PointF pointF1 = (PointF) animation.getAnimatedValue();
                iv.setX(pointF1.x);
                iv.setY(pointF1.y);
            }
        });
        objectAnimator.start();
    }

    public void startAnimation(View view) {
        final ImageView iv = (ImageView) view;

        ObjectAnimator oa = ObjectAnimator.ofFloat(iv, "translationY", 0f,1000f);
        oa.setDuration(800);
        oa.setInterpolator(new AccelerateDecelerateInterpolator());

        oa.start();
    }