使用片段标记片段、标记
在Android中，你可以设置标签在FragmentTransaction一个片段。
In Android, you can set a tag for a Fragment in a FragmentTransaction.
为什么我需要设置标签的片段？
Why would I need to set a tag for a Fragment?
和它是很好的做法，如果一个片段改变基于它的标签自己的行为？
And is it good practice if a Fragment changed its behavior based on its tag?
推荐答案
它可以用来避免重新创建一个片段在活动取向的变化。
It can be used to avoid re-creating a Fragment on Activity orientation change.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.photos_image_pager);
MyFragment fragment;
if (savedInstanceState != null) {
fragment = (MyFragment) getFragmentManager().findFragmentByTag("my_fragment_tag");
} else {
fragment = new MyFragment();
fragment.setArguments(getIntent().getExtras());
getFragmentManager().beginTransaction().add(android.R.id.content, fragment, "my_fragment_tag").commit();
}
}
在活动的是方向变化重新创建，它的的onCreate（...）方法被调用。如果片段的活动被摧毁，被添加到 FragmentManager 与标记，它现在可以从 FragmentManager 检索相同的标签。
The Activity is re-created on orientation change, and it's onCreate(...) method is called. If the Fragment was created before the Activity was destroyed and was added to the FragmentManager with a tag, it can now be retrieved from the FragmentManager by the same tag.
有关它如何被使用更长的讨论，请参见：
For a longer discussion on how it can be used, see:
ViewPager和片段 - 什么是正确的方式来存储片段的状态
