依靠两个fragment之间共同依靠的activity实现通信
核心代码
//找到另外一个fragment的实例
Fragment_2 f2= (Fragment_2) getActivity().getFragmentManager().findFragmentByTag("f2");
f2.update("你好");
主函数在调用时增加tag参数
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.ll1,new Fragment_1(),"f1");
fragmentTransaction.replace(R.id.ll2,new Fragment_2(),"f2");
//☆☆☆☆☆☆
fragmentTransaction.commit();
