[安卓] 20基于蓝牙BLE的广播包高频快速搜索 _高频

仓廪实则知礼节，衣食足则知荣辱。这篇文章主要讲述[安卓] 20基于蓝牙BLE的广播包高频快速搜索相关的知识，希望能为你提供帮助。

目录

前言：
1、初始化-onCreate
2、开始扫描-doDiscovery
3、监听
4、权限文件配置
5、最后说明

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【[安卓] 20基于蓝牙BLE的广播包高频快速搜索】新的：

// Device scan callback. private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() { @Override public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) { runOnUiThread(new Runnable() { @Override public void run() { if(device_filter(device)){ //mDevicesNameVector.add(device.getName()); //mDevicesAddrVector.add(device.getAddress()); //mRSSIVector.add((short)rssi); Log.d("RSSI",device.getAddress() + " " + device.getName() + " " + String.valueOf(rssi)); ... } } }); } };

老的：

// The BroadcastReceiver that listens for discovered devices and // changes the title when discovery is finished //【查找蓝牙设备】 private final BroadcastReceiver mReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { Log.d("onReceive","OK"); 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); mDevicesNameVector.add(device.getName()); mDevicesAddrVector.add(device.getAddress()); short rssi = intent.getExtras().getShort(BluetoothDevice.EXTRA_RSSI); mRSSIVector.add(rssi); Log.d("RSSI",device.getName()+""+String.valueOf(rssi)); // When discovery is finished, change the Activity title } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) { setProgressBarIndeterminateVisibility(false); if (mDevicesNameVector.size() != 0) { Message msg = new Message(); //消息 Bundle bundle = new Bundle(); bundle.clear(); Log.d("onReceive","1"); msg.what = 0x01; //消息类别 bundle.putShort("msg",(short) 0); Log.d("onReceive","2"); msg.setData(bundle); Log.d("onReceive","3"); myHandler.sendMessage(msg); Log.d("onReceive","4"); } } } };

可见：新的相对比较简单、可以持续不断的扫描获取（同一个设备会被不断的扫描到）；老的则分为两步：第一步是每次扫描到一次新设备都会有一个FOUND事件、最后停止扫描了还有个FINISH事件，这里我在FINISH事件结束时发出一个msg来通知进行其他操作。
4、权限文件配置新的：

< uses-permission a:name="android.permission.ACCESS_FINE_LOCATION"/> < uses-permission a:name="android.permission.ACCESS_COARSE_LOCATION"/> < uses-permission a:name="android.permission.BLUETOOTH"/> < uses-permission a:name="android.permission.BLUETOOTH_ADMIN"/> < uses-feature a:name="android.hardware.bluetooth_le" a:required="true"/>

老的：

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

可见：相差不大，新的比老的多了bluetooth_le说明。
5、最后说明当你尝试使用BLE SCAN之后，你会感觉有一种飞一般的感觉，几乎同一个设备每一秒都会被扫描到多次。拿这些高频扫描的大量数据，就可以做类似beacon、距离估算、定位等小应用了！效果会比老的scan方法要好很多～
LINKS
[1]. 本项目GITHUB链接地址
[2]. 在Linux下搭建安卓APP的开发烧写环境（makefile版）—— 在Linux上用命令行+VIM开发安卓APP
[3]. android developer TextView
[4]. android developer Vector
[5]. android developer String
[6]. android developer Formatter
[7]. android developer Matcher
[8]. android developer Pattern
[9]. 等宽字体-Android 设置字体的三种方法（TypeFace）
[10]. Android 设置TextView滑动滚动条和滑动效果