Dynamic Fragments 2

package com.mycompany.fragmentdemo;

import android.app.Activity;
import android.support.v4.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {

    Button clickButton;
    boolean status = false;//set our boolean up to load FragmentOne

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        clickButton = (Button)findViewById(R.id.btn1);
        clickButton.setText("Press to Load First Fragment");

        clickButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

             /* ///////////////////////////////// could put these outside
                of the if statements and it would work as well
                FragmentManager fragmentManager = getFragmentManager();
                FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
               ///////////////////////////////// */

                //if the value of the boolean status is true
                if (status == false)//so first button click have to load the first fragment
                {//have to create an object of the first fragment to begin.
                    FragmentOne frag1 = new FragmentOne();//step 1
                    //when you load
                    FragmentManager fragmentManager = getFragmentManager(); //step3
                    //we are not using intent here so we skill step 2
                    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
                    //now load the first fragement into the relative layout
                    //waiting for it on activity_main.xml
                    fragmentTransaction.add(R.id.target_container,frag1);//arguments are the container for the frag
                    //if you get an error here, one problem might be in your FragmentOne
                    //you are importing import android.support.v4.app.Fragment;
                    //you should try import android.app.Fragment;
                    //this error is often caused by loading the wrong libraries.
                    //How do you know? Read the library documents
                    // or just get to know what causes what errors and fix it.
                    fragmentTransaction.commit();
                    //now change the text on the button
                    clickButton.setText("Load 2nd Frag");
                    status = true;
                }
                else{
                    FragmentTwo frag2 = new FragmentTwo();//step 1
                    //we are not using intent here so we skill step 2
                    FragmentManager fragmentManager = getFragmentManager(); //step3
                    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();//step 4
                    fragmentTransaction.add(R.id.target_container, frag2);//step 5
                    fragmentTransaction.commit();//step 6
                    clickButton.setText("Load 1st Frag");
                    status = false;
                }

            }
        });
    }
}

package com.mycompany.fragmentdemo;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

/**
* A simple {@link Fragment} subclass.
*/
public class FragmentOne extends Fragment {

    public FragmentOne() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_one_layout, container, false);
    }

}

package com.mycompany.fragmentdemo;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

/**
* A simple {@link Fragment} subclass.
*/
public class FragmentTwo extends Fragment {

    public FragmentTwo() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_two_layout, container, false);
    }

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:andriod="http://schemas.android.com/apk/res-auto"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical">

    <Button
        android:layout_width="250dp"
        android:layout_height="wrap_content"
        android:text="Load First Fragment"
        android:id="@+id/btn1"

        android:layout_gravity="center" />
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="400dp"
        android:layout_marginTop="10dp"
        android:id="@+id/target_container"/>

    </LinearLayout>