java - 如何使用界面在两个 Activity 之间进行通信

我正在尝试在两个 Activity Act1 and Act2之间建立监听器接口(interface)。 Act1将以Act2开头。如果Act2中发生了某些事件，它将通知Act1。问题是我正在使用Intent开始新 Activity ，那么Act1如何将自己分配为Act2接口(interface)的监听器？

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:请不要建议我使用片段。我现在要使用 Activity 。

最佳答案

您是否考虑过使用LocalBroadcastManager？

在Act1的onCreate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onCreate中:

LocalBroadcastManager.getInstance(this).sendBroadcast(new Intent("activity-2-initialized"));

如果代码无法编译，请给我评论，我是手工编写的。