android - 为什么 Android 的 LocalBroadcastManager 没有运行？

Question

我不明白这段代码有什么问题。

Listener 在活动的 onCreate 中：

private BroadcastReceiver receiver;
private Context context;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
    context = getApplicationContext();

    receiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

            Log.e("MAIN onCreate: ", "It is never shown.");

        }
    };
}

寄存器在activity的onResumen中：

@Override
protected void onResume() {
    super.onResume();
    registerReceiver(receiver, new IntentFilter("receiveMyService"));
}

发件人在一个按钮中，我可以看到日志运行良好，但 test 的值为 false：

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        Intent intent = new Intent("receiveMyService");
        Boolean test = LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
        Log.e("Button", "It works but test is always false: " + test);
        return true;
    }
    return super.onOptionsItemSelected(item);
}

为什么 BroadcastReceiver - onReceive 的代码永远不会运行？

Answer 1

因为你注册了一个BroadcastReceiver不是LocalBroadcastReceiver
替换这个：

registerReceiver(receiver, new IntentFilter("receiveMyService"));

有了这个

LocalBroadcastManager.getInstance(this).registerReceiver(receiver, new IntentFilter("receiveMyService"));