作为标题,我在我的 APP 上使用了 ActionBarSherlock 和 SlidingMenu。
要在操作栏上添加菜单项,我所做的是:
public class Main extends SherlockFragmentActivity
{
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setTheme(R.style.Theme_Sherlock);
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
getSupportActionBar();
setContentView(R.layout.main);
FragmentManager fm=getSupportFragmentManager();
FragmentTransaction ft=fm.beginTransaction();
menuFrag=fm.findFragmentByTag("f1");
if(menuFrag==null)
{
menuFrag=new MenuFragment();
ft.add(menuFrag, "f1");
}
ft.commit();
//...other stuff
}
/**
* A fragment that displays a menu. This fragment happens to not
* have a UI (it does not implement onCreateView), but it could also
* have one if it wanted.
*/
@SuppressLint("ValidFragment")
public class MenuFragment extends SherlockFragment
{
public MenuFragment(){}
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
{
itemProgram=menu.add(0, MENU_ID_PROGRAMS, 0, getString(R.string.menuProgram));
itemProgram.setIcon(R.drawable.icon_programs_select).setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
itemMyList=menu.add(0, MENU_ID_MYLIST, 0, getString(R.string.menuMyList));
itemMyList.setIcon(R.drawable.icon_mylist).setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
itemPlaying=menu.add(0, MENU_ID_PLAYING, 0, getString(R.string.menuPlaying));
itemPlaying.setIcon(R.drawable.icon_playing).setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
}
}
}
在大多数情况下它运行良好,但有时我在启动我的应用程序时会收到此错误
android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment
make sure class name exists, is public, and has an empty constructor that is public
我的APP刚刚崩溃...
为了遵循该错误消息,我确实在 MenuFragment 上添加了一个空构造函数,但我的 APP 有时仍会因相同的错误而强制关闭。
我还在 StackOverflow 中阅读了一些关于此的主题,但还不够了解。
我能做些什么来克服这个问题?