通过代码添加片段并通过ViewPager管理它们

Question

我正在同时使用片段和ViewPagers。

The Issue Is

它正常工作，直到我尝试通过代码将更多片段添加到新布局中。

这是我的Video_Fragment类代码

import android.support.v4.app.Fragment;

public class Video_fragment extends Fragment{
    public static final String EXTRA_MESSAGE = "EXTRA_MESSAGE";
    public static final Video_fragment newInstance(String message)
    {
        Video_fragment f = new Video_fragment();
        Bundle bdl = new Bundle(1);
        bdl.putString(EXTRA_MESSAGE, message);
        f.setArguments(bdl);
        return f;

    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onActivityCreated(savedInstanceState);
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        String message = getArguments().getString(EXTRA_MESSAGE);
        View view = inflater.inflate(R.layout.video_fragment, container, false);


        TextView messageTextView = (TextView)view.findViewById(R.id.textView);
        messageTextView.setText(message);


        if(message.equals("Tv Shows"))
        {

        }
        if(message.equals("Movies"))
        {
        }
        if(message.equals("Music Videos"))
        {

        }
        return view;
    }

以下是我的Pager类的代码

public class MyPageAdapter extends FragmentPagerAdapter {
    private List<Fragment> fragments;

    public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) {
        super(fm);
        this.fragments = fragments;
    }

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

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


My Question Is

当我尝试使用这段代码通过代码输入新片段时，我不断收到错误SOURCE NOT FOUND

Video_content = (LinearLayout)findViewById(R.id.Content);
        android.support.v4.app.FragmentTransaction t = getSupportFragmentManager().beginTransaction();

        //Add first fragment
        myFragment1 = new Video_fragment();
        t.add(Video_content.getId(), myFragment1, "myFirstFragment");

        myFragment2 = new Video_fragment();
        t.add(Video_content.getId(), myFragment2, "mySecondFragment");

        myFragment3 = new Video_fragment();
        t.add(Video_content.getId(), myFragment3, "mySecondFragment");

        t.commit();

为什么会出现此错误？

这是我的FragmentActivity的完整代码

public class Video extends SherlockFragmentActivity {
    MyPageAdapter pageAdapter;
    ViewPager pager;
    LinearLayout Video_content;
    public static Video_fragment myFragment1;
    public static Video_fragment myFragment2;
    public static Video_fragment myFragment3;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setTheme(SampleList.THEME);
        requestWindowFeature(Window.FEATURE_ACTION_BAR_OVERLAY);
        getSupportActionBar().setDisplayShowTitleEnabled(false);
        getSupportActionBar().setBackgroundDrawable(getResources().getDrawable(android.R.color.transparent));

        setContentView(R.layout.activity_video);

        Video_content = (LinearLayout)findViewById(R.id.Content);
        android.support.v4.app.FragmentTransaction t = getSupportFragmentManager().beginTransaction();

        //Add first fragment
        myFragment1 = new Video_fragment();
        t.add(Video_content.getId(), myFragment1, "myFirstFragment");

        myFragment2 = new Video_fragment();
        t.add(Video_content.getId(), myFragment2, "mySecondFragment");

        myFragment3 = new Video_fragment();
        t.add(Video_content.getId(), myFragment3, "mySecondFragment");

        t.commit();

        DisplayMetrics metrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metrics);
        int screenWidth = metrics.widthPixels; 

        Button button1=(Button)findViewById(R.id.Tvshows);
        Button button2=(Button)findViewById(R.id.movies);
        Button button3=(Button)findViewById(R.id.music);

         List<Fragment> fragments = getFragments();

            pageAdapter = new MyPageAdapter(getSupportFragmentManager(), fragments);

            pager = (ViewPager)findViewById(R.id.viewpager);
            pager.setAdapter(pageAdapter);
            pager.setCurrentItem(0);
            button1.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    // TODO Auto-generated method stub
                    pager.setCurrentItem(0);
                }
            });
            button2.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    // TODO Auto-generated method stub
                    pager.setCurrentItem(1);
                }
            });
            button3.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    // TODO Auto-generated method stub
                    pager.setCurrentItem(2);
                }
                });



    }



     private List<Fragment> getFragments(){
            List<Fragment> fList = new ArrayList<Fragment>();


            fList.add(myFragment1);
            fList.add(myFragment2);
            fList.add(myFragment3);

            return fList;
        }

        private class MyPageAdapter extends FragmentPagerAdapter {
            private List<Fragment> fragments;

            public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) {
                super(fm);
                this.fragments = fragments;
            }
            @Override
            public Fragment getItem(int position) {
                return this.fragments.get(position);

            }

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

        @Override
        public boolean onCreateOptionsMenu(com.actionbarsherlock.view.Menu menu) {

            boolean isLight = SampleList.THEME == R.style.Theme_Sherlock_Light;

            menu.add("Search")
            .setIcon(isLight ? R.drawable.ic_search_inverse : R.drawable.ic_search)
            .setActionView(R.layout.collapsible_edittext)
            .setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS | MenuItem.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW);

            menu.add("")
            .setIcon(R.drawable.network)
            .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM | MenuItem.SHOW_AS_ACTION_WITH_TEXT);

            menu.add("14°")
            .setIcon(R.drawable.weather1)
            .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM | MenuItem.SHOW_AS_ACTION_WITH_TEXT);

            menu.add("00:00")
                .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM | MenuItem.SHOW_AS_ACTION_WITH_TEXT);        

            return true;
        } 


}