propertyanimator(属性动画)之valuesanimator(动画执行类) propertyanimator(属性动画)之valu

1：获取一张图片，用系统图片也行

2：代码实现属性动画

public class OtherActivity extends AppCompatActivity implements View.OnClickListener{ private int screenHeightPixels; private ImageView iv; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_other); //找控件 iv = (ImageView) findViewById(R.id.iv); Button bt_parabola = (Button) findViewById(R.id.bt_parabola); Button bt_verticalRun = (Button) findViewById(R.id.bt_verticalRun); bt_verticalRun.setOnClickListener(this); bt_parabola.setOnClickListener(this); //获取屏幕 DisplayMetrics metrics = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(metrics); //得到屏幕的高度 screenHeightPixels = metrics.heightPixels; }@Override public void onClick(View v) { switch (v.getId()) { case R.id.bt_parabola://抛物线 //获取动画执行类 ValueAnimator valueAnimator = new ValueAnimator(); //设置起始坐标 valueAnimator.setObjectValues(new PointF(0, 0)); valueAnimator.setDuration(3000); //插值器 valueAnimator.setInterpolator(new LinearInterpolator()); //设置类型估值 valueAnimator.setEvaluator(new TypeEvaluator【propertyanimator(属性动画)之valuesanimator(动画执行类)】() {@Override public PointF evaluate(float fraction, PointF startValue, PointF endValue) { // fraction = t / duration PointF pointF = new PointF(); // x方向200px/s ，则y方向0.5 * 10 * t pointF.x = 200 * fraction * 3; pointF.y = 300 * (fraction * 3) * (fraction * 3); return pointF; } }); valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { PointF pointF = (PointF) animation.getAnimatedValue(); //获取最终位置 iv.setX(pointF.x); iv.setY(pointF.y); } }); valueAnimator.start(); break; case R.id.bt_verticalRun://自由落体 //动画执行类 ValueAnimator animator = ValueAnimator.ofFloat(0, screenHeightPixels - iv.getHeight()); animator.setTarget(iv); animator.setDuration(4000).start(); animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { //获取平移位置 float hight = (float) animation.getAnimatedValue(); iv.setTranslationY(hight); } }); break; } } }

3：推荐博客http://blog.csdn.net/lmj623565791/article/details/38067475/