当设备方向改变时,为什么以下代码中的片段类别的onDestroy被记录两次,我不明白。有人能解释一下我做错了什么吗?
public class ExampleActivity extends Activity {
protected String LOG_TAG = ExampleActivity.class.getSimpleName();
private FrameLayout mFragmentHolder;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LogUtil.i(LOG_TAG, "onCreate");
setContentView(R.layout.activity_main);
mFragmentHolder = (FrameLayout) findViewById(R.id.root);
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(mFragmentHolder.getId(),MyFragment.newInstance());
ft.commit();
}
@Override
protected void onDestroy() {
super.onDestroy();
LogUtil.i(LOG_TAG, "onDestroy");
}
@Override
protected void onPause() {
super.onPause();
LogUtil.i(LOG_TAG, "onPause");
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
LogUtil.i(LOG_TAG, "onRestoreInstanceState");
}
@Override
protected void onResume() {
super.onResume();
LogUtil.i(LOG_TAG, "onResume");
}
@Override
protected void onStart() {
super.onStart();
LogUtil.i(LOG_TAG, "onStart");
}
@Override
protected void onStop() {
super.onStop();
LogUtil.i(LOG_TAG, "onStop");
}
}
这里是片段类的代码片段
public class MyFragment extends Fragment {
protected String LOG_TAG = MyFragment.class.getSimpleName();
public static Fragment newInstance(){
return new MyFragment();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.screen_login, container,
false);
return view;
}
@Override
public void onDestroy() {
super.onDestroy();
LogUtil.i(LOG_TAG, "onDestroy");
}
@Override
public void onPause() {
super.onPause();
LogUtil.i(LOG_TAG, "onPause");
}
@Override
public void onResume() {
super.onResume();
LogUtil.i(LOG_TAG, "onResume");
}
@Override
public void onStart() {
super.onStart();
LogUtil.i(LOG_TAG, "onStart");
}
@Override
public void onStop() {
super.onStop();
LogUtil.i(LOG_TAG, "onStop");
}
}
以下是来自logcat的输出:
01-17 22:04:34.661: I/BaseApplication(21513): [0.0.7]-[BaseApplication]-[main]-[01/17/2014 22:04:34] onConfigurationChanged
01-17 22:04:34.706: I/MyFragment(21513): [0.0.7]-[MyFragment]-[main]-[01/17/2014 22:04:34] onPause
01-17 22:04:34.711: I/ExampleActivity(21513): [0.0.7]-[ExampleActivity]-[main]-[01/17/2014 22:04:34] onPause
01-17 22:04:34.721: I/MyFragment(21513): [0.0.7]-[MyFragment]-[main]-[01/17/2014 22:04:34] onStop
01-17 22:04:34.726: I/ExampleActivity(21513): [0.0.7]-[ExampleActivity]-[main]-[01/17/2014 22:04:34] onStop
01-17 22:04:34.731: I/MyFragment(21513): [0.0.7]-[MyFragment]-[main]-[01/17/2014 22:04:34] onDestroy
01-17 22:04:34.736: I/ExampleActivity(21513): [0.0.7]-[ExampleActivity]-[main]-[01/17/2014 22:04:34] onDestroy
01-17 22:04:34.766: I/ExampleActivity(21513): [0.0.7]-[ExampleActivity]-[main]-[01/17/2014 22:04:34] onCreate
01-17 22:04:34.866: I/MyFragment(21513): [0.0.7]-[MyFragment]-[main]-[01/17/2014 22:04:34] onDestroy
01-17 22:04:34.876: I/ExampleActivity(21513): [0.0.7]-[ExampleActivity]-[main]-[01/17/2014 22:04:34] onStart
01-17 22:04:34.881: I/MyFragment(21513): [0.0.7]-[MyFragment]-[main]-[01/17/2014 22:04:34] onStart
01-17 22:04:34.886: I/ExampleActivity(21513): [0.0.7]-[ExampleActivity]-[main]-[01/17/2014 22:04:34] onRestoreInstanceState
01-17 22:04:34.891: I/ExampleActivity(21513): [0.0.7]-[ExampleActivity]-[main]-[01/17/2014 22:04:34] onResume
01-17 22:04:34.896: I/MyFragment(21513): [0.0.7]-[MyFragment]-[main]-[01/17/2014 22:04:34] onResume