动态注册广播接收器不起作用-BluetoothDevice.ACTION_FOUND [英] Register broadcast receiver dynamically does not work - BluetoothDevice.ACTION_FOUND

问题描述

使用Log类跟踪运行时表明onReceive()方法没有被调用，为什么?

Using Log class to track Runtime show that onReceive() methode does not called,why ?

动态注册广播接收器

 private void discoverDevices () {
    Log.e("MOHAB","BEFORE ON RECEIVE");

     mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            Log.e("MOHAB","ON RECEIVE");
            String action = intent.getAction();
            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // Get the BluetoothDevice object from the Intent
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                // Add the name and address to an array adapter to show in a ListView
                Bluetooth b = new Bluetooth(device.getName(),device.getAddress());
                list.add(b);
            }
        }
    };
    Log.e("MOHAB","create intentFilter");
    // Register the BroadcastReceiver
    IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
    registerReceiver(mReceiver, filter); // Don't forget to unregister during onDestroy

}

推荐答案

您错过的是您需要启动设备发现

What you missed is that you need to start a device discovery

首先，获取蓝牙适配器

BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();

此后，您可以通过调用

mBtAdapter.startDiscovery();

您也应该在此处阅读详细信息，例如关于cancelDiscovery() http://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#startDiscovery％28％29

You should read the details here as well, e.g. about cancelDiscovery() http://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#startDiscovery%28%29

PS .此外，根据官方文档，建议使用context.getSystemService(Context.BLUETOOTH_SERVICE)在API 18+上获取BluetoothAdapter.

P.S. Also, it is suggested to use context.getSystemService(Context.BLUETOOTH_SERVICE) to get the BluetoothAdapter on API 18+, according to official doc.

要获取代表本地蓝牙适配器的BluetoothAdapter， 在JELLY_BEAN_MR1及更低版本上运行时，请调用静态 getDefaultAdapter()方法；在JELLY_BEAN_MR2及更高版本上运行时， 通过带有BLUETOOTH_SERVICE的getSystemService(Class)检索它.

To get a BluetoothAdapter representing the local Bluetooth adapter, when running on JELLY_BEAN_MR1 and below, call the static getDefaultAdapter() method; when running on JELLY_BEAN_MR2 and higher, retrieve it through getSystemService(Class) with BLUETOOTH_SERVICE.

请注意，您需要startDiscovery()的 BLUETOOTH_ADMIN 权限

Be reminded that you need BLUETOOTH_ADMIN permission to startDiscovery()

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