Fragment와 AddToBackStack

Fragment에서, add나 Replace를 한 후, back버튼을 누르면, 이전 Fragment를 복원해 줄 수 있다.
바로, addToBackStack() 메소드를 이용한다.

샘플 코드는 다음과 같다.  

1. FragmentExample04Activity.java

package fragment.example04;

import android.app.Activity;

import android.app.FragmentTransaction;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.LinearLayout;

public class FragmentExample04Activity extends Activity {

private Button addFragmentBtn;

private int currentIdx = 1;

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        

        addFragmentBtn = (Button) findViewById(R.id.add_fragment);

        

        addFragmentBtn.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

FragmentTransaction ft = getFragmentManager().beginTransaction();

ft.replace(R.id.fragment_cont, new MyFragment(currentIdx));

ft.addToBackStack(null);

ft.commit();

currentIdx++;

}

});

    }

}

 
2. main.xml

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

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

    android:orientation="horizontal"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent">

    <LinearLayout

    android:id="@+id/fragment_cont"

    android:layout_weight="1"

    android:layout_width="0dip"

    android:layout_height="match_parent" />

    <Button

    android:id="@+id/add_fragment"

    android:layout_weight="0"

    android:layout_width="wrap_content"

    android:layout_height="match_parent"

    android:text="Add Fragment" />

</LinearLayout>

 
3. MyFragment.java

package fragment.example04;

import android.app.Fragment;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

public class MyFragment extends Fragment {

private int currentCnt;

public MyFragment(int _currentCnt){

this.currentCnt = _currentCnt;

}

@Override

public View onCreateView(LayoutInflater inflater, ViewGroup container,

Bundle savedInstanceState) {

View view = inflater.inflate(R.layout.fragment, null);

((TextView) view.findViewById(R.id.title)).setText(currentCnt + "번째 Fragment.!");

return view;

}

}

 4. fragment.xml

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

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

    android:orientation="vertical"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent">

<TextView

            android:id="@+id/title"  

   android:layout_width="fill_parent" 

   android:layout_height="fill_parent" 

   android:text="@string/hello"  />

</LinearLayout>

 
위코드를 작성해 주면 된다. 

완성 화면은 다음과 같다. 

우측의 Add Fragment를 누르면, Fragment가 더해지며,

하단의 <- 버튼을 눌러주게 되면, 이전의 Fragment가 복원된다.