Android cainiao Study Notes 27 ---- simple use of Fragment, androidfragment

Android cainiao Study Notes 27 ---- simple use of Fragment, androidfragment

1. FragmentLifecycle:

Simply create a new MyFragment inherited from Fragment, override each lifecycle callback method, and directly output information that identifies the function called.

Override the lifecycle callback methods of MainActivity and output the identity information.

MyFragment. java:

  1 public class MyFragment extends Fragment {  2   3       @Override  4   5       public void onActivityCreated(Bundle savedInstanceState) {  6   7            // TODO Auto-generated method stub  8   9            super.onActivityCreated(savedInstanceState); 10  11            Log.i("FRAGMENT","onActivityCreated()"); 12  13       } 14  15       @Override 16  17       public View onCreateView(LayoutInflater inflater, ViewGroup container, 18  19                  Bundle savedInstanceState) { 20  21            // TODO Auto-generated method stub 22  23            Log.i("FRAGMENT","onCreateView()"); 24  25            TextView textView = new TextView(getActivity()); 26  27            textView.setText("This is a fragment"); 28  29            return textView; 30  31       } 32  33       @Override 34  35       public void onDestroyView() { 36  37            // TODO Auto-generated method stub 38  39            super.onDestroyView(); 40  41            Log.i("FRAGMENT","onDestroyView()"); 42  43       } 44  45       @Override 46  47       public void onAttach(Activity activity) { 48  49            // TODO Auto-generated method stub 50  51            super.onAttach(activity); 52  53            Log.i("FRAGMENT","onAttach()"); 54  55       } 56  57       @Override 58  59       public void onCreate(Bundle savedInstanceState) { 60  61            // TODO Auto-generated method stub 62  63            super.onCreate(savedInstanceState); 64  65            Log.i("FRAGMENT","onCreate()"); 66  67       } 68  69       @Override 70  71       public void onStart() { 72  73             // TODO Auto-generated method stub 74  75            super.onStart(); 76  77            Log.i("FRAGMENT","onStart()"); 78  79       } 80  81       @Override 82  83       public void onResume() { 84  85            // TODO Auto-generated method stub 86  87            super.onResume(); 88  89            Log.i("FRAGMENT","onResume()"); 90  91       } 92  93       @Override 94  95       public void onPause() { 96  97            // TODO Auto-generated method stub 98  99            super.onPause();100 101            Log.i("FRAGMENT","onPause()");102 103       }104 105       @Override106 107       public void onStop() {108 109            // TODO Auto-generated method stub110 111            super.onStop();112 113            Log.i("FRAGMENT","onStop()");114 115       }116 117       @Override118 119       public void onDestroy() {120 121            // TODO Auto-generated method stub122 123            super.onDestroy();124 125            Log.i("FRAGMENT","onDestroy()");126 127       }128 129       @Override130 131       public void onDetach() {132 133            // TODO Auto-generated method stub134 135            super.onDetach();136 137            Log.i("FRAGMENT","onDetach()");138 139       }140 141 }

Note: A View object must be returned in the onCreateView () method.

MainActivity. java:

 1 public class MainActivity extends ActionBarActivity { 2  3     @Override 4  5     protected void onCreate(Bundle savedInstanceState) { 6  7         super.onCreate(savedInstanceState); 8  9         setContentView(R.layout.activity_main);10 11         Log.i("ACTIVITY","onCreate()");12 13     }14 15       @Override16 17       protected void onStop() {18 19            // TODO Auto-generated method stub20 21            super.onStop();22 23            Log.i("ACTIVITY","onStop()");24 25       }26 27       @Override28 29       protected void onDestroy() {30 31            // TODO Auto-generated method stub32 33            super.onDestroy();34 35            Log.i("ACTIVITY","onDestroy()");36 37       }38 39       @Override40 41       protected void onPause() {42 43            // TODO Auto-generated method stub44 45            super.onPause();46 47            Log.i("ACTIVITY","onPause()");48 49       }50 51       @Override52 53       protected void onResume() {54 55            // TODO Auto-generated method stub56 57            super.onResume();58 59            Log.i("ACTIVITY","onResume()");60 61       }62 63       @Override64 65       protected void onStart() {66 67            // TODO Auto-generated method stub68 69            super.onStart();70 71            Log.i("ACTIVITY","onStart()");72 73       }74 75       @Override76 77       protected void onRestart() {78 79            // TODO Auto-generated method stub80 81            super.onRestart();82 83            Log.i("ACTIVITY","onRestart()");84 85       }86 87 }

Layout file:

1 <fragment2 3         android:id="@+id/frag"4 5         android:name="cn.csc.fragment.MyFragment"6 7         android:layout_width="wrap_content"8 9         android:layout_height="wrap_content"/>

 

Note: you must use the name attribute to specify the permission name of the newly created fragment.

Running result:

 

Press the BACK button of the simulator:

 

Dalvik is inserted in the middle for garbage collection, but the overall order has not changed:

The calling process of each callback function throughout the lifecycle is as follows:

Display to front-end:

Append MyFragment onAttach () to activity

MyFragment onCreate () fragment Creation

MyFragment onCreateView () fragment create your own view

MainActivity onCreate () activity Creation

MyFragment onActivityCreated ()

MainActivity onStart ()

MyFragment onStart ()

MainActivity onResume ()

MyFragment onResume ()

Press the back key

MyFragment onPause ()

MainActivity onPause ()

MyFragment onStop ()

MainActivity onStop ()

MyFragment onDestoryView () destroys its own view

MyFragment onDestory ()

MyFragment onDetach () Relationship between release and activity

MainActivity onDetory ()

 

2.A simple two-FragmetFor example, click one of the following changes:

1) Create a New MyFragment inherited from ListFragment:

Public class MyFragment extends ListFragment {@ Override public void onActivityCreated (Bundle savedInstanceState) {// TODO Auto-generated method stub super. onActivityCreated (savedInstanceState); setListAdapter (new ArrayAdapter <String> (getActivity (), android. r. layout. simple_list_item_activated_1, android. r. id. text1, new String [] {"6:00", "6:30", "7:20", "8:00", "8:40"}) ;}@ Override public void onListItemClick (ListView l, view v, int position, long id) {// TODO Auto-generated method stub super. onListItemClick (l, v, position, id); // set it to single-choice mode, and click getListView (). setChoiceMode (ListView. CHOICE_MODE_SINGLE); getListView (). setItemChecked (position, true); FragmentManager fm = getFragmentManager (); FragmentTransaction ft = fm. beginTransaction (); Fragment fr = new TmpFragment (position); ft. replace (R. id. frame, fr); ft. commit ();}}

2) create TmpFragment inherited from Fragment:

1 public class TmpFragment extends Fragment {2 3 private int index; 4 5 private static String [] items = new String [] {"Get up and wash", "punch For A Walk ", "Have Breakfast", "", "punch"}; 6 7 public TmpFragment (int index) {8 9 super (); 10 11 this. index = index; 12 13} 14 15 @ Override16 17 public View onCreateView (LayoutInflater inflater, ViewGroup container, 18 19 Bundle savedInstanceState) {20 21 // TODO Auto-generated method stub22 23 TextView TV = new TextView (getActivity (); 24 25 TV. setText (items [index]); 26 27 return TV; 28 29} 30 31}

3) Layout file:

 1 <fragment 2  3         android:id="@+id/frag" 4  5         android:name="cn.csc.fragment1.MyFragment" 6  7         android:layout_width="0dp" 8  9         android:layout_height="match_parent"10 11         android:layout_weight="1"12 13         />14 15     <FrameLayout16 17         android:id="@+id/frame"18 19         android:layout_width="0dp"20 21         android:layout_height="wrap_content"22 23         android:layout_weight="1">24 25 </FrameLayout> 

4) running result:

 

 

The above is the simple learning of Fragment, and you should study it carefully when necessary ......