Question

我创建了一个帮助类，它扩展了BroadcastReceiver，以监听发现的BluetoothDevice和发现完成意图。我有两个通过传递处理程序来使用此类的活动。处理程序根据意图接收消息。我像这样实例化类和registerReceiver：

来自mainActivity ：

deviceHelper=new DevicesHelper(myHandler,DevicesHelper.REQUEST_DETECT_DEVICES_IN_RANGE);

IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(deviceHelper, filter);

filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(deviceHelper, filter);

if(myBluetoothAdapter.isDiscovering())myBluetoothAdapter.cancelDiscovery();
myBluetoothAdapter.startDiscovery();

来自ListActivity ：

deviceHelper=new DevicesHelper(deviceListHandler,DevicesHelper.REQUEST_DEVICE_LIST_ACTIVITY);

IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(deviceHelper, filter);

filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(deviceHelper, filter);

DeviceHelper类：

public class DevicesHelper extends BroadcastReceiver {

    public final static int REQUEST_DEVICE_LIST_ACTIVITY=1;
    public final static int REQUEST_DETECT_DEVICES_IN_RANGE=2;


    Handler myHandler;      
    int requestCode;

    public DevicesHelper(){

    }
    public DevicesHelper(Handler handler,int requestCode){
            this.requestCode=requestCode;
            myHandler=handler;

    }

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        String action = intent.getAction();

        // When discovery finds a device
        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

        if (BluetoothDevice.ACTION_FOUND.equals(action)) {
            // Get the BluetoothDevice object from the Intent
            switch(requestCode){
            case REQUEST_DEVICE_LIST_ACTIVITY: 
                if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    //newDevicesCount++;
                    String[] deviceInfo={device.getName(),device.getAddress()};

                    myHandler.obtainMessage(DeviceListActivity.MESSAGE_NEW_DEVICE,deviceInfo);
                };


                break;

            case REQUEST_DETECT_DEVICES_IN_RANGE:

                String[] deviceInfo={device.getName(),device.getAddress()};

                myHandler.obtainMessage(StripChartRecorder.MESSAGE_NEW_DEVICE,deviceInfo);
                break;

            }


            // When discovery is finished, change the Activity title
        } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {

            myHandler.obtainMessage(StripChartRecorder.MESSAGE_DISCOVERY_FINISHED);

        }
    }

处理程序：

private final Handler myHandler=new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch(msg.what) {
                case MESSAGE_NEW_DEVICE:
                    doOtherStuff();

                case MESSAGE_DISCOVERY_FINISHED:
                    dostuff();
            }
            break;
}}

我在这里遗漏了什么吗？我感谢任何帮助。

Answer 1

您需要sendMessage(Message msg)其中，msg是您Message获得的obtainMessage。

Answer 2

问题是我如何处理从处理程序收到的消息。变成了Set＆lt;＆gt;最初根据eclipse的指令设置为null，因此它从不添加从BroadcastReceiver助手类接收的设备。我感谢任何试图提供帮助的人。

扩展BroadcastReceiver的类不起作用

2 个答案: