Java “无效”时,InvalidateOptions菜单()不工作;“重新启动”;活动
我有一个活动,我们称之为FirstActivity.java,它有一个actionBar,带有一个通过片段实例化的导航抽屉。在这个片段中,NavigationDrawerFragment.java,我将方法放在CreateOptions菜单(菜单菜单菜单,菜单充气机)、Options ItemSelected(菜单项)和PrepareOptions菜单(菜单菜单菜单)上,就像任何人通常那样实例化actionBar。在actionBar的右侧,我有一个带有“messages”图标的按钮,该图标指向用户的收件箱片段。当收到新消息时,我在第一个活动中调用InvalidateOptions菜单(),并在OnPrepareOptions菜单(菜单)中将图标更改为更亮的图标。到目前为止一切正常 问题是:我可以通过导航抽屉中的一个选项离开FirstActivity。我是通过意图来做的。我们称之为SecondActivity.javaJava “无效”时,InvalidateOptions菜单()不工作;“重新启动”;活动,java,android,android-fragments,android-activity,android-actionbar,Java,Android,Android Fragments,Android Activity,Android Actionbar,我有一个活动,我们称之为FirstActivity.java,它有一个actionBar,带有一个通过片段实例化的导航抽屉。在这个片段中,NavigationDrawerFragment.java,我将方法放在CreateOptions菜单(菜单菜单菜单,菜单充气机)、Options ItemSelected(菜单项)和PrepareOptions菜单(菜单菜单菜单)上,就像任何人通常那样实例化actionBar。在actionBar的右侧,我有一个带有“messages”图标的按钮,该图标指向
Intent myIntent = new Intent(FirstActivity.this, SecondActivity.class);
startActivity(myIntent);
finish();
当我再次调用FirstActivity(也是通过Intent)时,invalidateOptions函数()方法停止工作。它不会触发方法onCreateOptions菜单或onPrepareOptions菜单。我也尝试过SupportInvalidateOptions菜单(),但运气不佳
只有当我点击菜单按钮(在actionBar的左侧)时,这些方法才会被调用,消息图标才会改变。有人知道这种奇怪行为的原因吗
更好的是,有人知道我的问题的解决方案吗?:)
FirstActivity.java
public class FirstActivity extends ActionBarActivity impements NavigationDrawerFragment.NavigationDrawerCallbacks {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.first_activity);
// When a new message arrives
if (thereIsAnIncomingMessage) {
invalidateOptionsMenu();
}
}
}
public class NavigationDrawerFragment extends Fragment {
private RelativeLayout relativeLayout;
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
relativeLayout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
return relativeLayout;
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
menu.clear();
inflater.inflate(R.menu.menu_main, menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.action_menu) {
// Open navigation drawer menu
return mDrawerToggle.onOptionsItemSelected(item) || super.onOptionsItemSelected(item);
} else if (item.getItemId == R.id.action_chat) {
// Open messages fragment
MessagesFragment messagesFragment = new MessagesFragment();
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.container, messagesFragment, "MESSAGES_FRAGMENT");
fragmentTransaction.addToBackStack("chatFrag");
fragmentTransaction.commit();
}
}
@Override
public void onPrepareOptionsMenu(Menu menu) {
super.onPrepareOptionsMenu(menu);
if (FirstActivity.thereIsAnIncomingMessage) {
menu.getItem(0).setIcon(R.drawable.new_message_icon);
} else {
menu.getItem(0).setIcon(R.drawable.message_icon);
}
}
public interface NavigationDrawerCallbacks {
void onNavigationDrawerItemSelected(int position);
}
}
first_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" android:id="@+id/first_activity_layout">
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".FirstActivity">
<!-- As the main content view, the view below consumes the entire
space available using match_parent in both dimensions. -->
<FrameLayout android:id="@+id/container" android:layout_width="match_parent"
android:layout_height="match_parent" />
<!-- android:layout_gravity="start" tells DrawerLayout to treat
this as a sliding drawer on the left side for left-to-right
languages and on the right side for right-to-left languages.
If you're not building against API 17 or higher, use
android:layout_gravity="left" instead. -->
<!-- The drawer is given a fixed width in dp and extends the full height of
the container. -->
<fragment android:id="@+id/navigation_drawer"
android:layout_width="@dimen/navigation_drawer_width" android:layout_height="match_parent"
android:layout_gravity="start"
android:name="com.example.Controller.Main.NavigationBar.NavigationDrawerFragment"
tools:layout="@layout/fragment_navigation_drawer" />
</android.support.v4.widget.DrawerLayout>
</LinearLayout>
问题是当您点击后退按钮时,
FirstActivity
的OnCreate
方法没有被调用。相反,您可以将代码放在恢复时的中,如下所示:
@Override
public void onResume(){
super.onResume();
if(thereIsAnIncomingMessage)
invalidateOptionsMenu();
}
请参阅官方文档。我认为invalidateOptionsMenu()可能触发了“old”onPrepareOptionsMenu,但片段回栈条目计数始终为0(零)。仍在调查。。。