android 2.2和android 6与蓝牙接口的区别

Question

我写了一个代码，在蓝牙设备附近扫描API8级，但现在当我要使用同样的API23级应用程序时，它就扫描失败了。除了蓝牙功能之外，其他功能都运行得很好。有人能说出工作哪里出了问题吗？我附上了一个在API8上工作但不能在API23上工作的示例代码

public class MyBluetoothScanActivity extends AppCompatActivity {
Button bt,bt_count;
ListView listView;
BluetoothAdapter btAdapter;
Set<BluetoothDevice> devicesArray;
IntentFilter filter;
BroadcastReceiver receiver;
ArrayAdapter<String> listAdapter;
ArrayList<String> pairedDevices;
ArrayList<BluetoothDevice> devices;
int count=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my_bluetooth_scan);

    bt=(Button) findViewById(R.id.bT_scan2);
    bt.setTransformationMethod(null);

    bt_count=(Button) findViewById(R.id.bt_count);
    bt_count.setTransformationMethod(null);

    bt_count.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Toast.makeText(getBaseContext(),"Count: "+count,Toast.LENGTH_SHORT ).show();
        }
    });




    listView=(ListView) findViewById(R.id.listViewscan);

    btAdapter = BluetoothAdapter.getDefaultAdapter();
    filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);

    if(!btAdapter.isEnabled()){
        turnOnBT();
    }


    init();

    bt.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            newScan();
        }
    });


    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            if(btAdapter.isDiscovering()){
                btAdapter.cancelDiscovery();
            }
            if(!listAdapter.getItem(i).contains("Paired")){
                try {
                    BluetoothDevice selectedDevice = devices.get(i);
                    pairDevice(selectedDevice);
                    Thread.sleep(500);
                    newScan();
                }
                catch (Exception e){}
            }
            else{
                BluetoothDevice selectedDevice = devices.get(i);
                Intent intent=new Intent(getBaseContext(),BtIns.class);
                intent.putExtra("MAC",selectedDevice.getAddress());
                startActivity(intent);
            }
        }
    });
}

private void newScan(){
    btAdapter.cancelDiscovery();
    Toast.makeText(getBaseContext(),"New Scan Start",Toast.LENGTH_SHORT ).show();

    listAdapter= new ArrayAdapter<String>(getBaseContext(), android.R.layout.simple_list_item_1,0);
    listView.setAdapter(listAdapter);

    devices = new ArrayList<BluetoothDevice>();
    btAdapter.startDiscovery();
}
private void getPairedDevices() {
    devicesArray = btAdapter.getBondedDevices();
    if(devicesArray.size()>0){
        for(BluetoothDevice device:devicesArray){
            pairedDevices.add(device.getName());

        }
    }
}

void turnOnBT(){
    Intent intent =new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivity(intent);
}

void init(){

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

            String action = intent.getAction();

            //Toast.makeText(getBaseContext(),"new br: "+action,Toast.LENGTH_LONG ).show();

            if(BluetoothDevice.ACTION_FOUND.equals(action)){

                pairedDevices=new ArrayList<String>();
                getPairedDevices();
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

                //Toast.makeText(getBaseContext(),"Dev: "+device.getName(),Toast.LENGTH_LONG ).show();
                devices.add(device);
                String s = "";
                for(int a = 0; a < pairedDevices.size(); a++){
                    if(device.getName().equals(pairedDevices.get(a))){
                        //append
                        s = "(Paired)";
                        break;
                    }
                }

                listAdapter.add(device.getName()+" "+s+" "+"\n"+device.getAddress());

            }
            else if(BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)){
                if(btAdapter.getState() == btAdapter.STATE_OFF){
                    turnOnBT();
                }
            }


        }
    };
}

private void pairDevice(BluetoothDevice device) {
    try {
        Method m = device.getClass().getMethod("createBond", (Class[]) null);
        m.invoke(device, (Object[]) null);
    } catch (Exception e) {
        Toast.makeText(getBaseContext(),"Exception: "+e.getMessage(),Toast.LENGTH_LONG ).show();
    }
}

@Override
protected void onPause() {
    super.onPause();
    try {
        unregisterReceiver(receiver);
        btAdapter.cancelDiscovery();
    }
    catch (Exception e){}
}


@Override
public void onResume() {
    super.onResume();
    try {
        Toast.makeText(getBaseContext(),"Registration",Toast.LENGTH_SHORT ).show();
        registerReceiver(receiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
        registerReceiver(receiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        registerReceiver(receiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
        registerReceiver(receiver, filter);
    }
    catch (Exception e){}
}}

Answer 1

在API 23和更高版本上扫描蓝牙或Wi-Fi设备需要首先获得Location权限。此外，您还必须确保在设置中启用了位置。

使用谷歌Play服务，你可以检查位置设置，并使用SettingsApi.checkLocationSettings()应用程序接口请求启用它们，例如

final LocationRequest locationRequest = LocationRequest.create();
locationRequest.setPriority(LocationRequest.PRIORITY_LOW_POWER);

final LocationSettingsRequest request = new LocationSettingsRequest.Builder()
        .addLocationRequest(locationRequest)
        .setAlwaysShow(true)
        .setNeedBle(true)
        .build();

mPendingResult = SettingsApi.checkLocationSettings(mClient, request);

请参阅：https://developers.google.com/android/reference/com/google/android/gms/location/SettingsApi

要请求权限，首先需要在清单中声明权限，并在扫描之前请求权限。请参阅此处的文档：https://developer.android.com/training/permissions/requesting.html