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

In my case it was wrong namespace in menu.xml:

Pay attention to app:actionProviderClass="android.support.v7.widget.ShareActionProvider": it should have

• correct package (android.widget android.support.v7.widget)
• correct namespace (android app).

Unfortunatelly, the compiler compiles it without errors, only Android Studio makes notification with underlining.