Android Fragments

Introduction

Introduced in API 11. They are a small piece of UI and must have an Activity. Fragments can be added or removed from the Activity. They allow you to capture the UI functionality where you may need to share it across different activities. If we look at phone vs tablet we might this it more appropriate to use to activities but the UI code will remain the same.

Creating Layout

Create a subclass of fragment

public class HelloFragment extends Fragment {

        private static final String TAG = HelloFragment.class.getSimpleName();

        @Override
        public void onAttach(Context context) {
                super.onAttach(context);
                Log.i(TAG, "onAttach");
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                Log.i(TAG, "onCreate");
        }

        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
                Log.i(TAG, "onCreateView");
                return inflater.inflate(R.layout.fragment_hello, container, false);
        }

        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
                super.onActivityCreated(savedInstanceState);
                Log.i(TAG, "onActivityCreated");
        }


....

Create layout

<?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:background="#FF0"
                          android:orientation="vertical">

        <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                android:text="Hello From Fragment"
                android:textColor="@android:color/black"/>

</LinearLayout>

Link layout with Fragment