Android---Activity

 1 TextView mTextView;
 2 
 3 // some transient state for the activity instance
 4 String mGameState;
 5 
 6 @Override
 7 public void onCreate(Bundle savedInstanceState) {
 8     // call the super class onCreate to complete the creation of activity like
 9     // the view hierarchy
10     super.onCreate(savedInstanceState);
11 
12     // recovering the instance state
13     if (savedInstanceState != null) {
14         mGameState = savedInstanceState.getString(GAME_STATE_KEY);
15     }
16 
17     // set the user interface layout for this activity
18     // the layout file is defined in the project res/layout/main_activity.xml file
19     setContentView(R.layout.main_activity);
20 
21     // initialize member TextView so we can manipulate it later
22     mTextView = (TextView) findViewById(R.id.text_view);
23 }
24 
25 // This callback is called only when there is a saved instance that is previously saved by using
26 // onSaveInstanceState(). We restore some state in onCreate(), while we can optionally restore
27 // other state here, possibly usable after onStart() has completed.
28 // The savedInstanceState Bundle is same as the one used in onCreate().
29 @Override
30 public void onRestoreInstanceState(Bundle savedInstanceState) {
31     mTextView.setText(savedInstanceState.getString(TEXT_VIEW_KEY));
32 }
33 
34 // invoked when the activity may be temporarily destroyed, save the instance state here
35 @Override
36 public void onSaveInstanceState(Bundle outState) {
37     outState.putString(GAME_STATE_KEY, mGameState);
38     outState.putString(TEXT_VIEW_KEY, mTextView.getText());
39 
40     // call superclass to save any view hierarchy
41     super.onSaveInstanceState(outState);
42 }

 1 static final String STATE_SCORE = "playerScore";
 2 static final String STATE_LEVEL = "playerLevel";
 3 // ...
 4 
 5 
 6 @Override
 7 public void onSaveInstanceState(Bundle savedInstanceState) {
 8     // Save the user‘s current game state
 9     savedInstanceState.putInt(STATE_SCORE, mCurrentScore);
10     savedInstanceState.putInt(STATE_LEVEL, mCurrentLevel);
11 
12     // Always call the superclass so it can save the view hierarchy state
13     super.onSaveInstanceState(savedInstanceState);
14 }

 1 @Override
 2 protected void onCreate(Bundle savedInstanceState) {
 3     super.onCreate(savedInstanceState); // Always call the superclass first
 4 
 5     // Check whether we‘re recreating a previously destroyed instance
 6     if (savedInstanceState != null) {
 7         // Restore value of members from saved state
 8         mCurrentScore = savedInstanceState.getInt(STATE_SCORE);
 9         mCurrentLevel = savedInstanceState.getInt(STATE_LEVEL);
10     } else {
11         // Probably initialize members with default values for a new instance
12     }
13     // ...
14 }

1 public void onRestoreInstanceState(Bundle savedInstanceState) {
2     // Always call the superclass so it can restore the view hierarchy
3     super.onRestoreInstanceState(savedInstanceState);
4 
5     // Restore state members from saved instance
6     mCurrentScore = savedInstanceState.getInt(STATE_SCORE);
7     mCurrentLevel = savedInstanceState.getInt(STATE_LEVEL);
8 }

 1 public class MyActivity extends Activity {
 2      // ...
 3 
 4      static final int PICK_CONTACT_REQUEST = 0;
 5 
 6      public boolean onKeyDown(int keyCode, KeyEvent event) {
 7          if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
 8              // When the user center presses, let them pick a contact.
 9              startActivityForResult(
10                  new Intent(Intent.ACTION_PICK,
11                  new Uri("content://contacts")),
12                  PICK_CONTACT_REQUEST);
13             return true;
14          }
15          return false;
16      }
17 
18      protected void onActivityResult(int requestCode, int resultCode,
19              Intent data) {
20          if (requestCode == PICK_CONTACT_REQUEST) {
21              if (resultCode == RESULT_OK) {
22                  // A contact was picked.  Here we will just display it
23                  // to the user.
24                  startActivity(new Intent(Intent.ACTION_VIEW, data));
25              }
26          }
27      }
28  }