如何使用界面来进行两个活动之间的沟通
我试图让两个活动Act1 and Act2之间的监听器接口。 Act1将启动Act2 。 如果在Act2发生了一些事件，它会通知Act1 。 问题是我正在使用Intent开始新的活动，那么Act1如何将自己指定为Act2界面的侦听器呢？
Act1.java
public class Act1 extends ActionBarActivity implements ActionBar.OnNavigationListener { ActionBar actionbar; Intent pizzaIntent; boolean visibleFirstTime = true; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.menutab); //set actionbar here } @Override public boolean onNavigationItemSelected(int arg0, long arg1)// item pos, // itemid { switch (arg0) { case 0: if(this.visibleFirstTime == false) { if(pizzaIntent == null) { pizzaIntent = new Intent(this,Act2.class); //how to call setChangeListener? } startActivity(pizzaIntent); } else this.visibleFirstTime = false; break; case 1: System.out.println("selected: " + arg0); break; case 2: System.out.println("selected: " + arg0); break; case 3: System.out.println("selected: " + arg0); break; default: break; } return true; } }
Act2.java
public class Act2 extends Activity { selectionChangeListener listener; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.pizza_slice_selection); } public void setChangeListener(selectionChangeListener listener) { this.listener = listener; } private interface selectionChangeListener { public void selectionMadeAtIndex(int index); } }
注意：请不要build议我使用片段。 我目前想使用活动。
你有没有考虑使用LocalBroadcastManager ？
在Act1的创作中：
act2InitReceiver= new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { // do your listener event stuff } }; LocalBroadcastManager.getInstance(this).registerReceiver(act2InitReceiver, new IntentFilter("activity-2-initialized"));
在Act1的onDestroy中：
LocalBroadcastManager.getInstance(this).unregisterReceiver(act2InitReceiver);
在Act2的创作中：
LocalBroadcastManager.getInstance(this).sendBroadcast(new Intent("activity-2-initialized"));
如果代码不能编译，请给我一个评论，我正在用手写。
我会build议创build一个模型类。 让我举一个例子：
模型类：
public class CustomModel { public interface OnCustomStateListener { void stateChanged(); } private static CustomModel mInstance; private OnCustomStateListener mListener; private boolean mState; private CustomModel() {} public static CustomModel getInstance() { if(mInstance == null) { mInstance = new CustomModel(); } return mInstance; } public void setListener(OnCustomStateListener listener) { mListener = listener; } public void changeState(boolean state) { if(mListener != null) { mState = state; notifyStateChange(); } } public boolean getState() { return mState; } private void notifyStateChange() { mListener.stateChanged(); } }
以下是你将如何使用这个：
// Imports public class MainActivity extends Activity implements OnCustomStateListener { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); CustomModel.getInstance().setListener(this); boolean modelState = CustomModel.getInstance().getState(); Log.d(TAG, "Current state: " + String.valueOf(modelState)); Intent intent = new Intent(this, SecondActivity.class); startActivity(intent); } @Override public void stateChanged() { boolean modelState = CustomModel.getInstance().getState(); Log.d(TAG, "MainActivity says: Model state changed: " + String.valueOf(modelState)); } }
在第二项活动中更改成员状态：
// Imports public class SecondActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); CustomModel.getInstance().changeState(true); } }
LogCat输出：
Current state: false
MainActivity says: Model state changed: true
最简单的方法是使用静态对象，如下所示：
class Act1 extends Activity { static String msg1 = "Hi"; } class Act2 extends Activity { String msg2; public onCreate() { msg2 = Act1.msg1; } }
避免复杂性，保持简单和愚蠢。
