蓝牙无法在较新的手机/平板电脑中找到附近的设备

Question

我试图使用蓝牙找到附近的设备，该代码适用于Android版本4和5.0.2，但是当在三星galaxy s7和s8（都是版本7）上尝试相同的代码时，我可以看到广播接收器的信息“ ACTION_DISCOVERY_STARTED“和”ACTION_DISCOVERY_FINISHED“，但他们无法找到任何设备。

代码：

 @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
                    IntentFilter filter = new IntentFilter();

                    filter.addAction(BluetoothDevice.ACTION_FOUND);
                    filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);

        filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);

                    registerReceiver(mReceiver, filter);
                    if (adapter.isDiscovering()) {
                        adapter.cancelDiscovery();
                    }
                    adapter.startDiscovery();
    }

        private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
            public void onReceive(Context context, Intent intent) {
                String action = intent.getAction();

                if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
                    //discovery starts
                    showToast("BroadcastReceiver" + " ACTION_DISCOVERY_STARTED");
                    Log.v("BroadcastReceiver", "ACTION_DISCOVERY_STARTED");
                } else if 
                   (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                    //discovery finishes
                    Log.v("BroadcastReceiver", "ACTION_DISCOVERY_FINISHED");
                    showToast("BroadcastReceiver" + "ACTION_DISCOVERY_FINISHED");
                } else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                    //bluetooth device found
                    BluetoothDevice device = (BluetoothDevice) 
                    intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

                    Log.v("Found device ", "Found device " + device.getName());
                    showToast("Found device " + device.getName());
                }
            }
        };

menifest：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.ramile.myapplication">

    <uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>