اضافه کردن viewpager به اکتیویتی توسط کد جاوا

آیا کد من در اضافه کردن viewpager به اکتویتی ایرادی توش هست ؟

 public class MainFragment extends FragmentActivity {

    private ViewPager    mPager;
    private PagerAdapter mPagerAdapter;
    private LinearLayout LinearLayout;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        LinearLayout = new LinearLayout(this);
        LinearLayout.setOrientation(LinearLayout.VERTICAL);
        LayoutParams linLparam = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
        LinearLayout.setBackgroundColor(Color.parseColor(("#000000")));

        mPager = new ViewPager(this);
        LayoutParams pagerLparam = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        mPager.setLayoutParams(pagerLparam);

        FragmentOne fragmentOne = new FragmentOne();
        FragmentTwo fragmentTwo = new FragmentTwo();

        mPagerAdapter = new PagerAdapter(getSupportFragmentManager());
        mPagerAdapter.addFragment(fragmentOne);
        mPagerAdapter.addFragment(fragmentTwo);

        mPager.setAdapter(mPagerAdapter);
        LinearLayout.addView(mPager);

        setContentView(LinearLayout, linLparam);

        // initPaging();
    }
}


public class PagerAdapter extends FragmentPagerAdapter {

    private final List<Fragment> mFragments = new ArrayList<Fragment>();


    public PagerAdapter(FragmentManager manager) {
        super(manager);
    }


    public void addFragment(Fragment fragment) {
        mFragments.add(fragment);
        notifyDataSetChanged();
    }


    @Override
    public int getCount() {
        return mFragments.size();
    }


    @Override
    public Fragment getItem(int position) {
        return mFragments.get(position);
    }
}