android---fragment的生命周期

 第一个Fragment被加载  -----Fragment1->>onAttach -----Fragment1->>onCreate -----Fragment1->>onCreateView -----Fragment1->>onActivityCreated -----Fragment1->>onStart -----Fragment1->>onResume 第二个Fragment进来 -----Fragment1->>onPause -----Fragment1->>onStop -----Fragment1->>onDestroyView -----Fragment2->>onAttach -----Fragment2->>onCreate -----Fragment2->>onCreateView -----Fragment2->>onActivityCreated -----Fragment2->>onStart -----Fragment2->>onResume 第三个Fragment进来 -----Fragment2->>onPause -----Fragment2->>onStop -----Fragment2->>onDestroyView  回退到第二个Fragment -----Fragment2->>onCreateView -----Fragment2->>onActivityCreated -----Fragment2->>onStart -----Fragment2->>onResume