recyclerView.setHasFixedSize方法什么时候设置为true什么时候设置为false呢?可以看下源码中关于这个方法的解释:/***RecyclerViewcanperformseveraloptimizationsifitcanknowinadvancethatRecyclerView's*sizeisnotaffectedbytheadaptercontents.RecyclerViewcanstillchangeitssizebased*onotherfactors(e.g.itsparent'ssize)butthissizecalculationcannotdep