Android之Fragment学习心得

1.fragment必须要有唯一标识，在xml文件中指定id或者tag

2.在xml文件中必须指定class

3.生命周期与Activity共存如下图

4.可以使用FragmentTransaction在一个activity之中添加、删除和替换Fragment

public void addFragment(View view) {
ft = fm.beginTransaction();
ft.add(R.id.fl_group, new ButtonFragment(),"fg_button");
ft.addToBackStack(null);
ft.commit();
}

public void removeFragment(View view) {
ft = fm.beginTransaction();
Fragment fragment = fm.findFragmentByTag("fg_button");
ft.remove(fragment);
ft.commit();
}

public void replaceFragment(View view) {
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.fl_group, new TextViewFragment(), "fg_textView");
ft.commit();
}

5.将添加、删除和替换的Fragment加入到Fragment back stack

ft = fm.beginTransaction();
ft.add(R.id.fl_group, new ButtonFragment(),"fg_button");
String tag = "fg_button";
ft.addToBackStack(tag);
ft.commit();

6.默认的过渡动画：ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_*);

7.Fragment与activity之间的通信

Activity继承接口，进行扩展，Fragment调用接口方法，最终由Activity内的方法执行。