最近客户需求,android系统的一个设备,想连接一个扫描枪(类似蓝牙键盘,只支持hid协议),并且可以收到其数据,填写到输入框中。我这里借了一个蓝牙鼠标,用来与android设备连接。
HID设备(Hunman Interface Device Profile),即人机交互设备,常见的有鼠标,键盘,游戏手柄,等等。一般有线方式都是通过USB连线连接到机器设备,作为用户输入设备。在蓝牙技术中,HID设备的接入就是无线的了。
网上查资料说hid从android4.0开始支持(可能是usb hid),不过蓝牙hid应该从android4.2开始支持的,如下图所示:
android4.1.2中的Bluetooth应用中没有hid的相关代码,而android4.2源码中Bluetooth应用中才有hid的代码。
连接hid设备步骤:
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if (mBluetoothAdapter == null) { Toast.makeText(this, "不支持蓝牙功能", 0).show(); // 不支持蓝牙 return; } // 如果没有打开蓝牙 if (!mBluetoothAdapter.isEnabled()) { mBluetoothAdapter.enable(); } // 初始化广播接收者 mBroadcastReceiver = new BlueBroadcastReceiver(); IntentFilter intentFilter = new IntentFilter(); intentFilter.addAction(BluetoothDevice.ACTION_FOUND); intentFilter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED); intentFilter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED); intentFilter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED); intentFilter.addAction("android.bluetooth.input.profile.action.CONNECTION_STATE_CHANGED"); this.registerReceiver(mBroadcastReceiver, intentFilter);
// 4.2以上才支持HID模式
if (Build.VERSION.SDK_INT >= 17) {
mHidUtil = HidUtil.getInstance(this);
}
public static HidUtil getInstance(Context context){ if(null == instance){ instance = new HidUtil(context); } return instance; } private HidUtil(Context context) { this.context = context; mBtAdapter = BluetoothAdapter.getDefaultAdapter(); try { mBtAdapter.getProfileProxy(context, mListener, INPUT_DEVICE); } catch (Exception e) { e.printStackTrace(); } }
通过BluetoothAdapter对象调用getProfileProxy()函数获取代理蓝牙输入设备代理对象。
其中参数mListener必须实现BluetoothProfile.ServiceListener()。获取代理对象成功或失败都会回调该Listener。
private BluetoothProfile.ServiceListener mListener = new BluetoothProfile.ServiceListener() { @Override public void onServiceConnected(int profile, BluetoothProfile proxy) { Log.i(TAG, "mConnectListener onServiceConnected"); //BluetoothProfile proxy这个已经是BluetoothInputDevice类型了 try { if (profile == INPUT_DEVICE) { mBluetoothProfile = proxy; } } catch (Exception e) { e.printStackTrace(); } } @Override public void onServiceDisconnected(int profile) { Log.i(TAG, "mConnectListener onServiceConnected"); } };当连接代理服务成功,回调onServiceConnected()函数,失败则回调onServiceDisconnected()函数。
mBluetoothAdapter.startDiscovery();
if(action.equals(BluetoothDevice.ACTION_FOUND)){ // 通过广播接收到了BluetoothDevice final BluetoothDevice device = (BluetoothDevice) intent .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); if (device == null) return; String btname = device.getName(); String address = device.getAddress(); Log.i(TAG, "bluetooth name:"+btname+",address:"+address); if((address != null&& address.equals(HID_ADDR))||(btname != null && btname.equals(HID_NAME))){ mConnectDevice = device; mBluetoothAdapter.cancelDiscovery(); if(!mHidUtil.isBonded(device)){ //先配对 mHidUtil.pair(device); }else { //已经配对则直接连接 mHidUtil.connect(device); } } }HidUtil类中的配对方法:
/** * 配对 * @param BluetoothDevice */ public void pair(BluetoothDevice device) { Log.i(TAG, "pair device:"+device); Method createBondMethod; try { createBondMethod = BluetoothDevice.class.getMethod("createBond"); createBondMethod.invoke(device); } catch (Exception e) { e.printStackTrace(); } }
if(action.equals(BluetoothDevice.ACTION_BOND_STATE_CHANGED)){ BluetoothDevice device = intent .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); String name = device.getName(); String address = device.getAddress(); Log.i(TAG,"name:"+name+",address:"+address+",bondstate:"+device.getBondState()); if((address != null&& address.equals(HID_ADDR))||(name != null && name.equals(HID_NAME))){ if(device.getBondState() == BluetoothDevice.BOND_BONDED) mHidUtil.connect(device); } }
判断是否是要连接的输入设备,如果符合条件则进行连接。
HidUtil中connect 方法
/** * 连接设备 * @param bluetoothDevice */ public void connect(final BluetoothDevice device) { Log.i(TAG, "connect device:"+device); try { //得到BluetoothInputDevice然后反射connect连接设备 Method method = mBluetoothProfile.getClass().getMethod("connect", new Class[] { BluetoothDevice.class }); method.invoke(mBluetoothProfile, device); } catch (Exception e) { e.printStackTrace(); } }BluetoothInputDevice中的connect方法是隐藏的,所以需要通过反射机制获取该方法进行调用。
通过广播接收者监听连接状态。
if(action.equals("android.bluetooth.input.profile.action.CONNECTION_STATE_CHANGED")){ int state = intent.getIntExtra(BluetoothProfile.EXTRA_STATE,0); BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); Log.i(TAG,"state="+state+",device="+device); if(state == BluetoothProfile.STATE_CONNECTED){//连接成功 Toast.makeText(MainActivity.this, R.string.connnect_success, Toast.LENGTH_SHORT).show(); } else if(state == BluetoothProfile.STATE_DISCONNECTED){//连接失败 Toast.makeText(MainActivity.this, R.string.disconnected, Toast.LENGTH_SHORT).show(); } }
if(mConnectDevice != null) mHidUtil.disConnect(mConnectDevice);
HidUtil中disconnect方法
/** * 断开连接 * @param BluetoothDevice */ public void disConnect(BluetoothDevice device) { Log.i(TAG, "disConnect device:"+device); try { if (device != null) { Method method = mBluetoothProfile.getClass().getMethod("disconnect", new Class[] { BluetoothDevice.class }); method.invoke(mBluetoothProfile, device); } } catch (Exception e) { e.printStackTrace(); } }
adb shell
getevent -l
当连接成功后,会看到如下内容:
could not get driver version for /dev/input/mouse1, Not a typewriter
add device 7: /dev/input/event6
name: "Bluetooth Mouse"
这表示蓝牙鼠标成为一个输入设备。
左击鼠标:
/dev/input/event6: EV_MSC MSC_SCAN 00090001
/dev/input/event6: EV_KEY BTN_MOUSE DOWN
/dev/input/event6: EV_SYN SYN_REPORT 00000000
/dev/input/event6: EV_MSC MSC_SCAN 00090001
/dev/input/event6: EV_KEY BTN_MOUSE UP
/dev/input/event6: EV_SYN SYN_REPORT 00000000
我们应用中打印
03-13 12:08:36.526 I/MainActivity(23670): dispatchTouchEvent ev:MotionEvent { action=ACTION_DOWN, actionButton=0, id[0]=0, x[0]=269.7555, y[0]=543.9628, toolType[0]=TOOL_TYPE_MOUSE, buttonState=BUTTON_PRIMARY, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=16788085, downTime=16788085, deviceId=39, source=0x2002 }
03-13 12:08:36.653 I/MainActivity(23670): dispatchTouchEvent ev:MotionEvent { action=ACTION_UP, actionButton=0, id[0]=0, x[0]=269.7555, y[0]=543.9628, toolType[0]=TOOL_TYPE_MOUSE, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=16788216, downTime=16788085, deviceId=39, source=0x2002 }
表示在屏幕中某位置处点击了一下。
右击鼠标:
/dev/input/event6: EV_MSC MSC_SCAN 00090002
/dev/input/event6: EV_KEY BTN_RIGHT DOWN
/dev/input/event6: EV_SYN SYN_REPORT 00000000
/dev/input/event6: EV_MSC MSC_SCAN 00090002
/dev/input/event6: EV_KEY BTN_RIGHT UP
/dev/input/event6: EV_SYN SYN_REPORT 00000000
03-13 12:09:48.147 I/MainActivity(23670): dispatchKeyEvent event:KeyEvent { action=ACTION_DOWN, keyCode=KEYCODE_BACK, scanCode=0, metaState=0, flags=0x0, hwFlags=0x0, repeatCount=0, eventTime=16859701, downTime=16859701, deviceId=39, source=0x2002 }
03-13 12:09:48.147 I/MainActivity(23670): onKeyDown keyCode=4
03-13 12:09:48.308 I/InputDispatcher( 996): touch process [23670], send to pg
03-13 12:09:48.327 I/MainActivity(23670): dispatchKeyEvent event:KeyEvent { action=ACTION_UP, keyCode=KEYCODE_BACK, scanCode=0, metaState=0, flags=0x0, hwFlags=0x0, repeatCount=0, eventTime=16859870, downTime=16859870, deviceId=39, source=0x2002 }
03-13 12:09:48.327 I/MainActivity(23670): onKeyUp keyCode=4
03-13 12:09:48.337 I/MainActivity(23670): onBackPressed
表示点击了一下返回键,程序退出。
移动鼠标会发现屏幕上小光标在移动,滑动鼠标也会触发相应事件。
现在大部分手机是支持hid的,并且也将该功能打开状态。
如果是做系统开发,就需要注意将Bluetooth中的hid开关打开。
将源码中的packages/apps/Bluetooth/res/values/config.xml的profile_supported_hid 修改为true。
<bool name="profile_supported_hid">true</bool>
demo下载地址:http://download.csdn.net/detail/vnanyesheshou/9815127。
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