片段与不同的Viewpages

Question

I got some error messages in my android studio when make fragment like the pictures.

This is an error messages :

error: incompatible types: TabFragment2 cannot be converted to Fragment

error: cannot find symbol method getSupportFragmentManager()

And this is my code :

PagerAdapter.java

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;



public class PagerAdapter extends FragmentStatePagerAdapter {
    int mNumOfTabs;

    public PagerAdapter(FragmentManager fm, int NumOfTabs) {
        super(fm);
        this.mNumOfTabs = NumOfTabs;
    }

    @Override
    public Fragment getItem(int position) {

        switch (position) {
            case 0:
                TabFragment1 tab1 = new TabFragment1();
                return tab1;
            case 1:
                TabFragment2 tab2 = new TabFragment2();
                return tab2;
            case 2:
                TabFragment3 tab3 = new TabFragment3();
                return tab3;
            default:
                return null;
        }
    }

    @Override
    public int getCount() {
        return mNumOfTabs;
    }
}

TabFragment2.java

import android.app.Fragment;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


public class TabFragment2 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.tab_fragment_2, container, false);
        TabLayout tabLayout = (TabLayout) view.findViewById(R.id.tab_layout);
        tabLayout.addTab(tabLayout.newTab().setText("Image-1"));
        tabLayout.addTab(tabLayout.newTab().setText("Image-2"));
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

        final ViewPager viewPager = (ViewPager) view.findViewById(R.id.pager);
        final PagerAdapter adapter = new PagerAdapter (getActivity().getSupportFragmentManager(), tabLayout.getTabCount());
        viewPager.setAdapter(adapter);
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });
        return view;
    }
}

Answer 1

TabFragment2.java应该导入android.support.v4.app.Fragment而不是import android.app.Fragment;