Question

我有2个活动在运行。首先启动活动A，然后启动活动B.（即堆叠中的A，焦点中的B）。我有两个活动BroadcastReceiver。问题是只有活动A能够捕获我的广播消息（使用sendBroadcast）

为什么会这样？如何启用两个活动以接收广播而不终止（在活动A上调用finish）

另外，有什么办法可以在Activity A中重用Broadcast接收器方法吗？

广播活动

Intent intent = new Intent(MESSAGE_UPDATE);
intent.putExtra("message", message);
sendBroadcast(intent);

活动A

@Override
public void onResume() {
    super.onResume();
    if(resumeHasRun==false){
    IntentFilter movementFilter;
    movementFilter = new IntentFilter();

    movementFilter.addAction(NewService.MESSAGE_UPDATE);

    registerReceiver(mIntentReceiver, movementFilter);
    resumeHasRun=true;
    return;
    }
}
public BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String message = intent.getStringExtra("message");
                    updateTable(message);


    }
};

@Override
protected void onDestroy() {
    super.onDestroy();
  unregisterReceiver(mIntentReceiver);
}

public void startNewActivity(){
    Intent newIntent = new Intent(getApplicationContext(),ActivityB.class);
    startActivity(newIntent);
    //never call finish
}

活动B

@Override
public void onResume() {
    super.onResume();
    if(resumeHasRun==false){
    IntentFilter movementFilter;
    movementFilter = new IntentFilter();

    movementFilter.addAction(NewService.MESSAGE_UPDATE);

    registerReceiver(mIntentReceiver, movementFilter);
    resumeHasRun=true;
    return;
    }
}
public BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String message = intent.getStringExtra("message");
                    updateAnotherTable(message);


    }
};
@Override
protected void onDestroy() {
    super.onDestroy();
  unregisterReceiver(mIntentReceiver);
}

Answer 1

移动：

registerReceiver(mIntentReceiver, movementFilter); to onStart()
unregisterReceiver(mIntentReceiver); to onStop()

制作（在自己的文件中）：

public class TableUpdateReceiver extends BroadcastReceiver {
    public interface Listener {
       public void tableUpdate(String message);
    };
    Listener mListener;

    public TableUpdateReceiver(Listener list) {
         mListener = list;
    }
    @Override
    public void onReceive(Context context, Intent intent) {
        String message = intent.getStringExtra("message");
        if(mListener != null) {
            mListener.tableUpdate(message);  
        } 
    }
};

让您的活动实现TableUpdateReceiver.Listener和：

public BroadcastReceiver mIntentReceiver;
onCreate(Bundle savedState) {
   ...
   mIntentReceiver = new TableUpdateReceiver(this);
   ...
}

public void tableUpdate(String message) {
   //do something
}

Answer 2

请参阅this example它可以帮助您解决问题。在两个活动中注册并进行抽象类活动。

广播到应用程序中的2个运行活动

2 个答案: