Android invalidateOptionsMenu() for API < 11

问题:

I used ActivityCompat.invalidateOptionsMenu(MainActivity.this); so that my menu item "refresh" can automatically be enabled/disabled without the using have to touch the "Menu" option (imagine the user leaves the Menu open... I need the "Refresh" menu item to automatically disabled and enable itself).

The ActivityCompat.invalidateOptionsMenu(MainActivity.this) works fine in Android 11+. But what can I use for android API < 11 ? :S I've searched so much but I cannot find an answer. Can anyone please help me on this?

This works fine in Android API 11+, using the onPrepareOptionsMenu and ActivityCompat.invalidateOptionsMenu(MainActivity.this). The issue is trying to get it done in Android API < 11.

Here is my onPrepareOptionsMenu method:

@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    if(menuRefreshEnable){
        menu.getItem(0).setEnabled(true);
    }
    if(!menuRefreshEnable){
        menu.getItem(0).setEnabled(false);
    }       
    return true;
}

回答1:

On API < 11 use supportInvalidateOptionsMenu() method

回答2:

ActivityCompat.invalidateOptionsMenu() doesn't callback onPrepareOptionsMenu(); it just update the menu directly. Just put some Log.d() and check out by yourself.

This works for me (I'm using API 8):

private Menu mMenu;
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.track_fragment, menu);
    mMenu = menu;
    }
...
private void someMethod() {
...
    if (mMenu != null) {
       MenuItem item = mMenu.findItem(R.id.new_track);
       if (item != null) {
            item.setVisible(false);
            ActivityCompat.invalidateOptionsMenu(this.getActivity());
        }
    }
...
}

My someMethod() get called from several places, even before onCreateOptionsMenu(), so I must check mMenu != null.

回答3:

This will return true if the API is above or equal to 11 and therefore supported. Before API 11, the menu is drawn when the menu button is pressed so there is no need for this method as it occurs automatically.