android.support.v4.app.Fragment

package com.example.duoduo.festival_sms;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import com.example.duoduo.festival_sms.fragment.FestivalCategoryFragment;
public class MainActivity extends AppCompatActivity {
    private TabLayout mTabLayout;
    private ViewPager mViewPager;
    private String[] mTitles = new String[]{"节日短信", "发送记录"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initViews();
    }
    private void initViews() {
        mTabLayout = (TabLayout) findViewById(R.id.id_tablayout);
        mViewPager = (ViewPager) findViewById(R.id.id_viewpaer);
        mViewPager.setAdapter(new FragmentPagerAdapter(getSupportFragmentManager())
        {
            @Override
            public Fragment getItem(int position)
            {
                return new FestivalCategoryFragment();
            }
            @Override
            public int getCount()
            {
                return mTitles.length;
            }
            @Override
            public CharSequence getPageTitle(int position)
            {
                return mTitles[position];
            }
        });
        mTabLayout.setupWithViewPager(mViewPager);
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main,menu);
        return true;
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        return super.onOptionsItemSelected(item);
    }
}

return后面出错 是什么原因呢