why MenuItemCompat.getActionProvider returns null?

Question

I tried to use android.support.v7.widget.ShareActionProvider on actionbar in my app. So I followed the example from android document but got some issues.
Here\'s my m

Answer 1

If someone wants to keep progaurd on and still use the code:

ShareActionProvider mShareActionProvider = (ShareActionProvider)MenuItemCompat.getActionProvider(shareItem);

Just need to add to proguard:

-keep class android.support.v7.widget.ShareActionProvider { *; }