如何使用片段过渡为视图或按钮设置动画？

Question

I created a ViewPager with 5 fragments. Each fragment has a button. I want to rotate that button with fragment transition. What happens that all the five buttons rotate when I start the activity, so I only see the rotation of the button of the first fragment. This is the code I used for each fragment:

        @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.quote_1, container, false);

        quoteOneShareButton = rootView.findViewById(R.id.q_one_share_btn);
        //code to rotate share btn with fragment transition:
        RotateAnimation rotateAnimation1 = new RotateAnimation(0, 360, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
        rotateAnimation1.setDuration(1500);
        rotateAnimation1.setInterpolator(new LinearInterpolator());
        quoteOneShareButton.startAnimation(rotateAnimation1);
        //end of rotation code
        return rootView;
    }

I want the animation of each button to start only when I get to the fragment that contains it. Any help is appreciated. Thank you all.

Answer 1

That's because all 5 fragments get created almost the same time, so you shouldn't start the animation inside the onCreateView instead start it when the fragment is visible to the user.

You can achieve this by calling the onResume method inside each fragment, but you must call BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT behavior in the constructor of the ViewPager adapter.

@Override
public void onResume(){
    super.onResume();
    // animtion code..
}