Android getActivity() - undefined

У меня есть ошибки в моем классе MainActivity.

Ошибка: The method getActivity() is undefined for the type MainActivity

public class MainActivity extends SherlockFragmentActivity{
    PlaceSlidesFragmentAdapter mAdapter;
    ViewPager mPager;
    PageIndicator mIndicator;

    public static final String TAG = "detailsFragment";

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.main,
                container, false);

        mAdapter = new PlaceSlidesFragmentAdapter(getActivity()
                .getSupportFragmentManager());

        mPager = (ViewPager) view.findViewById(R.id.pager);
        mPager.setAdapter(mAdapter);

        mIndicator = (CirclePageIndicator) view.findViewById(R.id.indicator);
        mIndicator.setViewPager(mPager);
        ((CirclePageIndicator) mIndicator).setSnap(true);

        mIndicator
                .setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
                    @Override
                    public void onPageSelected(int position) {
                        Toast.makeText(MainActivity.this.getActivity(),
                                "Changed to page " + position,
                                Toast.LENGTH_SHORT).show();
                    }

                    @Override
                    public void onPageScrolled(int position,
                            float positionOffset, int positionOffsetPixels) {
                    }

                    @Override
                    public void onPageScrollStateChanged(int state) {
                    }
                });
        return view;
    }
}