对 控件进行 缩放动画，显示或者隐藏

点击编辑按钮 每个item 中的 imageView ivDel 会显示 或者隐藏

public boolean show = false;


    /** * 切换显示删除图标 */
    public void deleteToggle() {
        //getCount 为items.size()
        // maxPositon 为最大的下标
        int maxPosition = getCount() - 1;
        if (show) { //立即隐藏
        //遍历 找到有下标做的标记的ImageView ivDel;
        //对这个控件进行 缩放动画
        //原点缩放 宽 高 都是从1到0
            for (int i = 0; i <= maxPosition; i++) {
                final ImageView ivDel = (ImageView) listView.findViewWithTag("ivDel" + i);
                ObjectAnimator anim = ObjectAnimator.ofFloat(ivDel, "abc", 1f, 0f);
                anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                    @Override
                    public void onAnimationUpdate(ValueAnimator valueAnimator) {
                        float val = (Float) valueAnimator.getAnimatedValue();
                        ivDel.setScaleX(val);
                        ivDel.setScaleY(val);
                    }
                });
                anim.setDuration(500);
                anim.start();
            }
            show = false;
        } else { //立即显示
            for (int i = 0; i <= maxPosition; i++) {
                final ImageView ivDel = (ImageView) listView.findViewWithTag("ivDel" + i);
                ObjectAnimator anim = ObjectAnimator.ofFloat(ivDel, "abc", 0f, 1f);
                anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                    @Override
                    public void onAnimationUpdate(ValueAnimator valueAnimator) {
                        float val = (Float) valueAnimator.getAnimatedValue();
                        ivDel.setScaleX(val);
                        ivDel.setScaleY(val);
                    }
                });
                anim.setDuration(500);
                anim.start();
            }
            show = true;
        }
    }