如何修复Android错误“不允许后台执行：接收Intent {...}”

Question

所以我正在编写一个使用蓝牙发现设备的Android应用程序。这是我用来开始发现的代码。

try {
    myBluetoothAdapter.startDiscovery();
    Log.d("Bluetooth Started successfully","yes");
} catch (Error e) {
    Log.d("FAILED","Ya failed mate");
    e.printStackTrace();
}

然后我注册一个BroadcastReceiver来监视何时找到设备。这是我的代码

IntentFilter intentFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
final ArrayList<String> stringArrayList = new ArrayList<>();
final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(getApplicationContext(),android.R.layout.simple_list_item_1,stringArrayList);
final ListView listView = findViewById(R.id.listView);
listView.setAdapter(arrayAdapter);
BroadcastReceiver myReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
    String action = intent.getAction();
    Log.d("ACTION RECEIVED","Action was received");
    Log.d("Device Name", String.valueOf(intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE)));
    if (BluetoothDevice.ACTION_FOUND.equals(action)) {
        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
        stringArrayList.add(device.getName());
        arrayAdapter.notifyDataSetChanged();
        listView.invalidateViews();
    }
    }
};
registerReceiver(myReceiver,intentFilter);

listView，arrayAdapter和stringArrayList就是我“登录”的东西。

问题是每当我运行该代码时，我都会收到此错误并且我的代码无法运行。我假设它不起作用的原因是因为这个错误。

W/BroadcastQueue: Background execution not allowed: receiving Intent { act=android.bluetooth.adapter.action.DISCOVERY_STARTED flg=0x10 } to com.verizon.messaging.vzmsgs/com.verizon.vzmsgs.receiver.DevicePairingListener

有人能告诉我这个错误意味着什么，以及如何解决它？

我还发现Stack Overflow上的其他问题，其错误看起来非常相似;比如，它将在BOOT_COMPLETED，ACTION_POWER_DISCONECTED或BATTERY_LOW的上下文中，而不是蓝牙。那些与此类似的是怎样的。

Answer 1

我认为这是因为Android O的隐式广播禁令，要解决这个问题，你可以使你的targetSDKVersion小于26。你可以在这里找到更多https://commonsware.com/blog/2017/04/11/android-o-implicit-broadcast-ban.html

Answer 2

在我的情况下 - Android 9（API级别28）我必须在代码中定义我的BroadcastReceiver才能使它工作。

像这样（在我的情况下在服务中添加 - 无关紧要）

private MyReceiver myReceiver;

@Override
public void onCreate() {
    myReceiver = new MyReceiver();
    this.registerReceiver(myReceiver, new IntentFilter("android.intent.action.myreceiver"));
}


@Override
public void onDestroy() {
    super.onDestroy();
    unregisterReceiver(myReceiver);
}

private class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) {

        try {
            if (intent.getAction().equals("android.intent.action.myreceiver")) {
                //logic goes here
            }
        } catch (Exception e) {
            //some log goes here
        }
    }
}

像这样发送广播

Intent intentMy = new Intent();
intentMy.setAction("android.intent.action.myreceiver");
intentMy.putExtra("whatever", true);
sendBroadcast(intentMy);