//listview
recyclerView.setLayoutManager(new LinearLayoutManager(FirstActivity.this,LinearLayoutManager.VERTICAL,false));
//GridView
recyclerView.setLayoutManager(new GridLayoutManager(FirstActivity.this,3));
//橫向單行
recyclerView.setLayoutManager(new LinearLayoutManager(FirstActivity.this,LinearLayoutManager.HORIZONTAL,false));
//橫向多行
recyclerView.setLayoutManager(new GridLayoutManager(FirstActivity.this,3, OrientationHelper.HORIZONTAL,false));
//瀑布
recyclerView.setLayoutManager(new StaggeredGridLayoutManager(3, OrientationHelper.VERTICAL));