要研究Android中的三种动画，第一种是单个View的各种动画效果，第二种是两个Active切换时的动画效果，第三种是类似于Gif的Frame By Frame动画效果，其中View的各种动画包括在xml文件中定义和代码中定义两种方式。-To study the three kinds of animation in Android, the first single View, a variety of animation effects, the second switch when the two Active animation, and the third is similar to Gif Frame By Frame animation, in which Viewa variety of animation defined in the xml file and the code defined in two ways.