# rotation

## rotation相关知识

• 动态地图标注算法
Dynamic maps that allow continuous map rotations, e.g., on mobile devices, encounter new issues unseen in static map labeling before. We study the following dynamic map labeling problem: The input is a static, labeled map, i.e., a set P of points in the plane with attached nonoverlapping horizontal rectangular labels. The goal is to find a consistent labeling of P under rotation that maximizes the number of visible labels for all rotation angles such that
• ObjectAnimator
透明度alphaanimator = ObjectAnimator.ofFloat(textView, &quot;alpha&quot;, 1, 0, 1); alphaanimator.setDuration(3*1000); alphaanimator.start();旋转：rotationanimator = ObjectAnimator.ofFloat(textView, &quot;rotation&quot;, 0, 360, 0); rotationanimator.setDuration(3*1000); rotationanimator.start();大小： scaleanimator = ObjectAnimator.ofFloat(textView, &quot;scaleX&quot;, 0.5f, 1); scaleanimator.setDuration(3*1000); scaleanimator.start();背景色：bgcoloranimato
• Android 属性动画的使用
ObjectAnimator 使用属性动画有3种方法： 1、使用ObjectAnimator类； eg： ObjectAnimator.ofFloat(mImageView, &quot;translationX&quot;, 0, i * 100F).setDuration(1000).start(); (1)第一个参数为Object 一般为需要实现动画的对象。 (2)第二个为要实现的动画类型（String类型） 具体有&quot;translationX&quot;,&quot;translationY&quot;,&quot;rotation&quot;,&quot;alpha&quot;,&quot;scaleX&quot;等 (3)第三个为values数组值，一般为 从...到...。 2、使用PropertyValuesHolder类； eg:PropertyValuesHolder p1 = PropertyValuesHo
• ViewPager3D旋转效果
这是一个3D旋转效果的viewPager：ViewPager viewPager= (ViewPager) findViewById(R.id.viewPager);PagerAdapter实现几个方法getCount：返回数据源sizeisViewFromObject（）你pagerAdapter选中的内容是不是当成一个对象来处理的意思吧instantiateItem：instantiateItem将view添加，并且返回destroyItem：移除一个view3D旋转动画的实现&nbsp;viewPager.setPageTransformer(true, transformer);设置自定义旋转动画；&nbsp; &nbsp; @Override&nbsp; &nbsp; public void onTransform(View view, float position) {&nbsp; &nbsp; &nbsp; &nbsp; float rotation = 180f * position;&nb