Navigation Drawer and dynamically created fragment conflict - android-fragments

Question

I am using the default Navigation Drawer in android studio and I have a dynamically created fragment and use TabLayout to run it. It will run normally but as I try to load the same fragment from the navigation drawer i run into error. Please see below:
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.content.ContextCompat;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
public class Introduction extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
final RelativeLayout relativeLayout = new RelativeLayout(getActivity());
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
relativeLayout.setLayoutParams(layoutParams);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
final ImageView introImage = new ImageView(getActivity());
introImage.setId(R.id.introImageId);
introImage.setImageResource(R.drawable.introduction);
introImage.setAnimation(AnimationUtils.loadAnimation(this.getContext(), android.R.anim.slide_out_right));
introImage.setPadding(100, 100, 100, 100);
final TextView introText = new TextView(getActivity());
introText.setText(R.string.introduction_text);
// introText.setTextAppearance(android.R.style.TextAppearance_Medium);
introText.setTextSize(20);
introText.setPadding(25,25,25,25);
introText.setTextColor(ContextCompat.getColor(this.getContext(), R.color.colorPrimary));
params.addRule(RelativeLayout.BELOW, introImage.getId());
introText.setAnimation(AnimationUtils.loadAnimation(this.getContext(),android.R.anim.slide_in_left));
relativeLayout.addView(introText,params);
relativeLayout.addView(introImage);
return relativeLayout;
}
}
But as I try to load it from Navigation drawer I get an error Error:(115, 62) error: incompatible types: Introduction cannot be converted to Fragment
public boolean onNavigationItemSelected(MenuItem item) {
FragmentManager fn = getFragmentManager();
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_introduction) {
fn.beginTransaction().replace(R.id.content_frame,new Introduction()).commit();
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
TabPagerAdapter
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class TabPagerAdapter extends FragmentPagerAdapter {
int tabCount;
public TabPagerAdapter(FragmentManager fm, int numberOfTabs) {
super(fm);
this.tabCount=numberOfTabs;
}
#Override
public Fragment getItem(int position) {
switch (position){
case 0:
Introduction tab1= new Introduction();
return tab1;
default:
return null;
}
}

Answer 1

I replaced getFragmentManager(); with getSupportFragmentManager(); and its working
// FragmentManager fn = getFragmentManager();
FragmentManager fn = getSupportFragmentManager();