Android : Creating fragment tutorial

How to create fragment in Android?

Here are two examples.
In the first we  create it from Activity class.
In the second we create it from a layout.xml file.

First Example:

package com.mamutek.adding.fragment.android;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;

/**
 * @author Peter Gostincar
 */

public class MainActivity extends FragmentActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    
    FragmentManager fm = getSupportFragmentManager();
    Fragment f = fm.findFragmentById(R.id.fragmentContainer);
    
    if(f == null){
      f = new MainFragment();
      fm.beginTransaction()
        .add(R.id.fragmentContainer, f)
        .commit();
    }
  }
}

package com.mamutek.adding.fragment.android;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

/**
 * @author Peter Gostincar
 */

public class MainFragment extends Fragment{
  
private TextView mText;
  
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState){
    View v = inflater.inflate(R.layout.fragment_main, parent, false);
    
    mText = (TextView) v.findViewById(R.id.textView);
    mText.setText("From Activity");
    
    return v;
  }
}

activiti_main.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:id="@+id/fragmentContainer"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    />

fragment_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

Second Example:

package com.mamutek.fragment.from.xml;

import android.os.Bundle;
import android.app.Activity;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;

public class MainActivity extends FragmentActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  }
}

package com.mamutek.fragment.from.xml;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

/**
 * @author Peter Gostincar
 */

public class MainFragment extends Fragment{
  
  private TextView mText;
  
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState){
    View v = inflater.inflate(R.layout.fragment_main, parent, false);
    
    mText = (TextView) v.findViewById(R.id.textView);
    mText.setText("From Layout");
    
    return v;
  }
}

activiti_main.xml

<fragment xmlns:android="http://schemas.android.com/apk/res/android"

    android:id="@+id/fragmentContainer"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:name="com.mamutek.fragment.from.xml.MainFragment"

    />

fragment_main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

    <TextView

        android:id="@+id/textView"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" />

</LinearLayout>