不知道为什么,但是我从Playstore中的应用程序收到一些错误报告,其中包含以下消息：
- java.lang.IllegalStateException: Fragment NewsOverViewFragment{4062e840} not attached to Activity
- at android.support.v4.app.Fragment.getResources(Fragment.java:601)
- at de.dala.simplenews.ui.NewsOverViewFragment.shouldUseMultipleColumns(NewsOverViewFragment.java:153)
- at de.dala.simplenews.ui.NewsOverViewFragment.updateMenu(NewsOverViewFragment.java:145)
- at de.dala.simplenews.ui.NewsOverViewFragment.onCreateOptionsMenu(NewsOverViewFragment.java:139)
我已经做了一个修复,并检查片段是否附加到活动,但这只是“避免”的问题.在我看来,它不应该发生在onCreateOptionsMenu或onOptionsItemSelected中获取一个未附加状态.
为什么会发生这种情况？片段如何调用onCreateOptionsMenu / onOptionsItemSelected而不附加到活动？
问候
码：
- @Override
- public void onCreateOptionsMenu(Menu menu,MenuInflater inflater) {
- menu.clear();
- inflater.inflate(R.menu.news_overview_menu,menu);
- updateMenu();
- super.onCreateOptionsMenu(menu,inflater);
- }
- private void updateMenu(){
- boolean useMultiple = shouldUseMultipleColumns();
- ...
- }
- private boolean shouldUseMultipleColumns(){
- boolean useMultiple = false;
- Configuration config = getActivity().getResources().getConfiguration();
- switch (config.orientation) {
- case android.content.res.Configuration.ORIENTATION_LANDSCAPE:
- useMultiple = PrefUtilities.getInstance().useMultipleColumnsLandscape();
- break;
- case android.content.res.Configuration.ORIENTATION_PORTRAIT:
- useMultiple = PrefUtilities.getInstance().useMultipleColumnsPortrait();
- break;
- }
- return useMultiple;
- }
就像我说的,我现在检查片段是否附加,然后调用shouldUseMultipleColumns()来修复问题,但不能解释为什么这被称为首先…
编辑2：我的活动
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- ...
- if (savedInstanceState == null) {
- if (getIntent().getDataString() != null) {
- String path = getIntent().getDataString();
- FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
- currentFragment = CategoryModifierFragment.getInstance(path);
- transaction.replace(R.id.container,currentFragment).commit();
- } else {
- FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
- currentFragment = NewsOverViewFragment.getInstance(NewsOverViewFragment.ALL);
- transaction.replace(R.id.container,currentFragment).commit();
- }
- }
- ...
- }
这基本上是附件程序.但是,可以调用总是替换currentFragment的其他片段,这样我的NewsOverViewFragment就没有附加的机会.但即使是这种情况 – 为什么要调用onCreateOptionsMenu？
