前言：

之前介绍过很多蓝牙beacon、搜索、连接、通讯的文章。不过最近我发现：之前写的蓝牙广播包搜索的工程，搜索频率太慢，而且不能一直保持搜索状态。因此，这里探讨下高频蓝牙广播包扫描 —— 蓝牙BLE扫描。

注：本文将从对比之前慢的和现在快的两个工程进行展开

1、初始化-onCreate

新的：

// Get the local Bluetooth adapter // Initializes Bluetooth adapter. final BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE); mBluetoothAdapter = bluetoothManager.getAdapter();  // Ensures Bluetooth is available on the device and it is enabled. If not, // displays a dialog requesting user permission to enable Bluetooth. if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {     Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);     startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT); }

老的：

// Register for broadcasts when a device is discovered IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND); this.registerReceiver(mReceiver, filter); // Register for broadcasts when discovery has finished filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED); this.registerReceiver(mReceiver, filter);  // Get the local Bluetooth adapter mBtAdapter = BluetoothAdapter.getDefaultAdapter();

可见：老的是通过注册广播过滤条件BluetoothDevice.ACTION_FOUND和BluetoothAdapter.ACTION_DISCOVERY_FINISHED，来实现监听蓝牙设备扫描的发现和停止扫描事件。而mReceiver则是回调函数，接下来会介绍；新的暂时看不出啥头绪，仅仅获得bluetoothManager和mBluetoothAdapter，接下来会用到。

2、开始扫描-doDiscovery

新的：

// Start device discover with the BluetoothAdapter private void doDiscovery() {     // If we're already discovering, stop it     if (mBluetoothAdapter.isDiscovering()) {         mBluetoothAdapter.stopLeScan(mLeScanCallback);     }     // Request discover from BluetoothAdapter     //use filter not work!!!!!!!!!!     //UUID[] uuid_arrays = new UUID[1];     //uuid_arrays[0] = ParcelUuid.fromString(UUID_SERVICE).getUuid();     //mBluetoothAdapter.startLeScan(uuid_arrays,mLeScanCallback);     //Log.d("RSSI",uuid_arrays[0].toString() + "  " + UUID.randomUUID().toString());     mBluetoothAdapter.startLeScan(mLeScanCallback); }

老的：

// Start device discover with the BluetoothAdapter private void doDiscovery() {     // If we're already discovering, stop it     if (mBtAdapter.isDiscovering()) {         mBtAdapter.cancelDiscovery();     }     // Request discover from BluetoothAdapter     mBtAdapter.startDiscovery(); }

可见：区别在于一个是BLE操作、一个是普通蓝牙操作。

3、监听

新的：