Property动画实例1

/**
     * Constructs and returns an ObjectAnimator that animates between float values. A single
     * value implies that that value is the one being animated to. Two values imply starting
     * and ending values. More than two values imply a starting value, values to animate through
     * along the way, and an ending value (these values will be distributed evenly across
     * the duration of the animation).
     *
     * @param target The object whose property is to be animated. This object should
     * have a public method on it called <code>setName()</code>, where <code>name</code> is
     * the value of the <code>propertyName</code> parameter.
     * @param propertyName The name of the property being animated.
     * @param values A set of values that the animation will animate between over time.
     * @return An ObjectAnimator object that is set up to animate between the given values.
     */
    public static ObjectAnimator ofFloat(Object target, String propertyName, float... values) {
        ObjectAnimator anim = new ObjectAnimator(target, propertyName);
        anim.setFloatValues(values);
        return anim;
    }

中文翻译:

构建并返回一个objectanimator动画之间的浮点值。一个单一的值意味着这个值是一个被动画。双值意味着开始和结束值。超过2个值意味着一个起始值，通过一个方向动画的值，和一个结束值（这些值将均匀地分布在动画的持续时间）。

简单讲就是设置属性与属性的变化值

如: 

ObjectAnimator.ofFloat(example,"translationY",0,example.getHeight()).start();

实现view

从y:0->view的高度 这样一个相对于view 直线向下移动动画

又如旋转动画: 

ObjectAnimator.ofFloat(example,"rotation",0,360).setDuration(3000).start();

下面我们来看一看xml方式的创建:

1:需要在res文件下面创建一个animator文件夹

2：然后创建Animator resouce files

3:加载xml动画 系统提供一个类 AnimatorInflator 这个类的静态方法loadAnimator可以实现加载xml动画

4：绑定你需要展现的view身上，animator.setTarget(view);

Animator animatorr = AnimatorInflater.loadAnimator(this, R.animator.animator_rotation);
                animatorr.setTarget(example);
                animatorr.start();
xml的样板:
<?xml version="1.0" encoding="utf-8"?>
<objectAnimator
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="3000"
    android:propertyName="rotation"
    android:repeatMode="reverse"
    android:valueFrom="0"
    android:valueTo="360" />

在3.0之前有组合动画，属性动画业同样有:

代码方式:

AnimatorSet 是一个非常有意思的类，可以实现动画的组合
主要API有:
playTogether(Animator... items)  一起同时执行多个动画
playSequentially(Animator... items)   顺序执行多个动画，一个接一个
如:
     ObjectAnimator trans = ObjectAnimator.ofFloat(example, "translationY", 0, example.getHeight()).setDuration(3000);
                ObjectAnimator alpha = ObjectAnimator.ofFloat(example, "alpha", 1, 0).setDuration(3000);
                AnimatorSet set = new AnimatorSet();
                set.playTogether(trans,alpha);
                set.start();

实现的是移动并消失动画
xml方式:
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:ordering="together">

    <objectAnimator
        android:duration="3000"
        android:propertyName="translationY"
        android:valueFrom="0f"
        android:valueTo="200f"/>
    <objectAnimator
        android:duration="3000"
        android:propertyName="alpha"
        android:valueFrom="0.0f"
        android:valueTo="1.0f" />
</set>