android 蓝牙连接ble设备

    前段时间公司让帮忙做一个控制蓝牙设备的Android程序，主要就是给设备发一些命令。以前没接触过蓝牙相关的开发，所以查阅了大量的资料，最终鼓捣出来了，在此记录下    在这里蓝牙设备是服务端，因此程序只需要实现客户端连接蓝牙设备就行了    1.首先申请相关权限    前面两个是蓝牙相关的权限，后面两个是定位相关的权限，定位权限必须要给，否则会扫描不到蓝牙设备    <uses-permission android:name="android.permission.BLUETOOTH" /><uses-permission android:name="android.permission.BLUETOOTH_ADMIN" /><uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /><uses-feature android:name="android.hardware.location.gps" />

2 检测蓝牙是否开启，若未开启则去开启BluetoothManager bluetoothManager =(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);mBluetoothAdapter = bluetoothManager.getAdapter();

if (!mBluetoothAdapter.isEnabled()) {//去开启蓝牙Intent enabler = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);startActivityForResult(enabler, 205);       } else {

//开始扫描蓝牙设备    

}

3 开始扫描设备 mLeScanCallback = new BluetoothAdapter.LeScanCallback() {@Overridepublic void onLeScan(BluetoothDevice bluetoothDevice, int i, byte[] bytes) {//bluetoothDevice 就是扫描到的蓝牙设备，这里将扫描到的设备实时展示出来if (bluetoothDevices==null){bluetoothDevices=new ArrayList<>();}if (bluetoothDevice != null) {boolean isSame=false;for (BluetoothDevice device : bluetoothDevices) {if (bluetoothDevice.getAddress().equals(device.getAddress())){isSame=true;}}if (!isSame){bluetoothDevices.add(bluetoothDevice);Message message=new Message();handler.sendMessage(message);}}Log.e(TAG, "onReceive: ACTION_FOUND" + bluetoothDevice.getName() + bluetoothDevice.getAddress());}};mBluetoothAdapter.startLeScan(mLeScanCallback);textView.setText("扫描中...");4.连接蓝牙设备并初始化好各种回调 回调中是在子线程里这里需要注意 蓝牙设备每次发送和接收的字符也是有限制的的BluetoothGattCallback callback = new BluetoothGattCallback() {@Overridepublic void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {super.onConnectionStateChange(gatt, status, newState);if (newState == BluetoothGatt.STATE_CONNECTED) { // 连接成功runOnUiThread(new Runnable() {@Overridepublic void run() {Toast.makeText(BlueToothActivity.this, "连接成功", Toast.LENGTH_SHORT).show();}});gatt.discoverServices(); // 则去搜索设备的服务(Service)和服务对应Characteristic} else { // 连接失败runOnUiThread(new Runnable() {@Overridepublic void run() {try {bleGatt.close();} catch (Exception e) {e.printStackTrace();}Toast.makeText(BlueToothActivity.this, "连接失败", Toast.LENGTH_SHORT).show();finish();}});}}@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)@Overridepublic void onServicesDiscovered(BluetoothGatt gatt, int status) {super.onServicesDiscovered(gatt, status);if (status == BluetoothGatt.GATT_SUCCESS) { // 成功订阅runOnUiThread(new Runnable() {@Overridepublic void run() {setView(true);if (progressDialog.isShowing()) {progressDialog.dismiss();}}});services = gatt.getServices(); // 获得设备所有的服务characteristics = new ArrayList<>();descriptors = new ArrayList<>();BluetoothGattService lastGattService = services.get(services.size() - 1);BluetoothGattCharacteristic lastCharacteristic = lastGattService.getCharacteristics().get(lastGattService.getCharacteristics().size() - 1);characteristic = lastCharacteristic;Log.e(TAG, "onServicesDiscovered: " + characteristic.getUuid().toString());bleGatt.setCharacteristicNotification(characteristic, true);} else {runOnUiThread(new Runnable() {@Overridepublic void run() {Toast.makeText(BlueToothActivity.this, "订阅失败", Toast.LENGTH_SHORT).show();}});}}@Overridepublic void onMtuChanged(BluetoothGatt gatt, int mtu, int status) {super.onMtuChanged(gatt, mtu, status);if (status == BluetoothGatt.GATT_SUCCESS) {Toast.makeText(BlueToothActivity.this, "修改成功" + mtu, Toast.LENGTH_SHORT).show();}}@Overridepublic void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {super.onCharacteristicChanged(gatt, characteristic);setTimer(false);Log.e(TAG, "onCharacteristicChanged: " + characteristic.getStringValue(0));String tem = characteristic.getStringValue(0);tem = tem.trim();if (tem.startsWith("{")) {// Log.e(TAG, "onCharacteristicChanged: {");resultInfo = null;resultInfo = tem;} else if (tem.subSequence(tem.length() - 1, tem.length()).equals("}")) {// Log.e(TAG, "onCharacteristicChanged: }");if (resultInfo == null) {return;}resultInfo = resultInfo + tem;runOnUiThread(new Runnable() {@Overridepublic void run() {setView(true);Log.e(TAG, "run: showdialog" + resultInfo);try {// Log.e(TAG, "run: " );showDialog(resultInfo);resultInfo = null;} catch (JSONException e) {// Toast.makeText(BlueToothActivity.this, ""+resultInfo, Toast.LENGTH_SHORT).show();e.printStackTrace();}}});} else {// Log.e(TAG, "onCharacteristicChanged: null");if (tem.subSequence(tem.length() - 1, tem.length()).equals("}")) {return;}resultInfo = resultInfo + tem;}}@Overridepublic void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {super.onCharacteristicWrite(gatt, characteristic, status);Log.e(TAG, "onCharacteristicWrite: " + characteristic.getStringValue(0));if (BluetoothGatt.GATT_SUCCESS == status) { // 发送成功if (isLoop) {if (b == null) {return;}if (index + 20 < b.length - 1) {byte tem[] = Arrays.copyOfRange(b, index, index + 20);writeCharacteristic(new String(tem));} else {byte tem[] = Arrays.copyOfRange(b, index, b.length);writeCharacteristic(new String(tem));b = null;setTimer(true);isLoop = false;}index = index + 20;} else {runOnUiThread(new Runnable() {@Overridepublic void run() {Toast.makeText(BlueToothActivity.this, "发送成功", Toast.LENGTH_SHORT).show();Log.e(TAG, "run:发送成功2" );}});setTimer(true);}} else { // 发送失败runOnUiThread(new Runnable() {@Overridepublic void run() {Toast.makeText(BlueToothActivity.this, "发送失败", Toast.LENGTH_SHORT).show();}});}}@Overridepublic void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {super.onCharacteristicRead(gatt, characteristic, status);Log.e(TAG, "onCharacteristicRead: " + "蓝牙回复数据为" + characteristic.getValue().toString());}@Overridepublic void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {super.onReadRemoteRssi(gatt, rssi, status);}};Log.e(TAG, "init: 藍牙連接" );bleGatt = bluetoothDevice.connectGatt(this, false, callback);5 发送数据characteristic.setValue(tem);发送成功后会回调上面的 

onCharacteristicWrite 方法

蓝牙设备返回数据会回调onCharacteristicChanged 方法