蓝牙网关onConnectionState更改在棒棒糖上不起作用

Question

我目前有一种方法，可以写入BLE设备发出蜂鸣音。我的蓝牙回调如下：

public class ReadWriteCharacteristic extends BluetoothGattCallback {
    public ReadWriteCharacteristic(Context context, String macAddress, UUID service, UUID characteristic, Object tag, Activity activity) {
        mMacAddress = macAddress;
        mService = service;
        mCharacteristic = characteristic;
        mTag = tag;
        mContext = context;
        this.activity =activity;
        final BluetoothManager bluetoothManager =
                (BluetoothManager) mContext.getSystemService(Context.BLUETOOTH_SERVICE);
        mBluetoothAdapter = bluetoothManager.getAdapter();

    }

    final private static String TAG = "ReadCharacteristic";
    private Object mTag;
    private String mMacAddress;
    private UUID mService;
    private BluetoothManager mBluetoothManager = null;
    private BluetoothAdapter mBtAdapter = null;
    private BluetoothGatt mBluetoothGatt = null;
    private String mBluetoothDeviceAddress ="";
    private UUID mCharacteristic;
    BluetoothDevice device;
    private Activity activity;
    private BluetoothAdapter mBluetoothAdapter;
    private Context mContext;
    ReadWriteCharacteristic rc;

    private int retry = 5;


    public String getMacAddress() {
        return mMacAddress;
    }

    public UUID getService() {
        return mService;
    }

    public UUID getCharacteristic() {
        return mCharacteristic;
    }

    public byte[] getValue() { return mValue; }

    public void onError() {
        Log.w(TAG, "onError");
    }

    public void readCharacteristic(){
        if (retry == 0)
        {
            onError();
            return;
        }
        retry--;


                device = mBluetoothAdapter.getRemoteDevice(getMacAddress());


                mBluetoothManager = (BluetoothManager) mContext.getSystemService(Context.BLUETOOTH_SERVICE);
                int connectionState = mBluetoothManager.getConnectionState(device,
                        BluetoothProfile.GATT);

                if (device != null) {

                    if (connectionState == BluetoothProfile.STATE_DISCONNECTED)
                    {

                        // Previously connected device. Try to reconnect.
                        if (mBluetoothDeviceAddress != null
                                && getMacAddress().equals(mBluetoothDeviceAddress)
                                && mBluetoothGatt != null) {
                            Log.w(TAG, "Re-use GATT connection");
                            if (mBluetoothGatt.connect()) {
                                Log.w(TAG, "Already connected, discovering services");
                                mBluetoothGatt.discoverServices();
                                //return ;
                            } else {
                                Log.w(TAG, "GATT re-connect failed.");
                                return;
                            }
                        }

                        if (device == null) {
                            Log.w(TAG, "Device not found.  Unable to connect.");
                            return;
                        }
                        Log.w(TAG, "Create a new GATT connection.");
                        rc= ReadWriteCharacteristic.this;
                        Log.w(TAG, "Starting Read [" + getService() + "|" + getCharacteristic() + "]");
                        mBluetoothGatt = device.connectGatt(mContext, false, rc);
                        refreshDeviceCache(mBluetoothGatt);
                        mBluetoothDeviceAddress = getMacAddress();
                    } else {
                        Log.w(TAG, "Attempt to connect in state: " + connectionState);
                        if(mBluetoothGatt!=null)
                            mBluetoothGatt.close();
                        readCharacteristic();
                    }

                }

    }

    @Override
    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
        super.onConnectionStateChange(gatt, status, newState);

        Log.w(TAG,"onConnectionStateChange [" + status + "|" + newState + "]");


        if ((newState == 2)&&(status ==0)) {
            gatt.discoverServices();
        }
        else if(status == 133 )
        {
            //gatt.disconnect();
            gatt.close();
            mBluetoothGatt = null;
            try
            {
                Thread.sleep(2000);
            }
            catch(Exception e)
            {

            }
            readCharacteristic();
        }
        else{

            if(mBluetoothGatt!=null)
                mBluetoothGatt.close();

           // gatt.close();

            Log.w(TAG, "[" + status + "]");
            //gatt.disconnect();

            try
            {
                Thread.sleep(2000);
            }
            catch(Exception e)
            {

            }
            mBluetoothGatt = null;
            readCharacteristic();
        }
    }



    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
        Log.w(TAG,"onServicesDiscovered [" + status + "]");
        BluetoothGattService bgs = gatt.getService(getService());
        if (bgs != null) {
            BluetoothGattCharacteristic bgc = bgs.getCharacteristic(getCharacteristic());
            gatt.readCharacteristic(bgc);
        }
    }

    @Override
    public void onCharacteristicWrite(BluetoothGatt gatt,
                                      BluetoothGattCharacteristic characteristic,
                                      int status) {
        Log.w(TAG,"onCharacteristicWrite [" + status + "]");
        if (status == BluetoothGatt.GATT_SUCCESS) {
            Log.w(TAG,"onCharacteristicWrite [" + getDataHex(characteristic.getValue()) + "]");
           // gatt.disconnect();
            if(mBluetoothGatt!=null)
                mBluetoothGatt.close();
          //  gatt.close();
          //  mBluetoothGatt=null;
        }
        else if(status ==133)
        {
            gatt.close();
            try
            {
                Thread.sleep(2000);
            }
            catch(Exception e)
            {

            }

            readCharacteristic();
        }

        else{
            //gatt.disconnect();
            gatt.close();

        }
    }

    @Override
    public void onCharacteristicRead(BluetoothGatt gatt,
                                     BluetoothGattCharacteristic characteristic,
                                     int status) {
        Log.w(TAG,"onCharacteristicRead [" + status + "]");
        if (status == BluetoothGatt.GATT_SUCCESS) {
            mValue = characteristic.getValue();
            // Perform write operations
            gatt.writeCharacteristic(bgc);


        }

        else if(status ==133)
        {
            gatt.close();
            try
            {
                Thread.sleep(2000);
            }
            catch(Exception e)
            {

            }

            readCharacteristic();
        }

        else {
          //  gatt.disconnect();
            gatt.close();
        }
    }

}

此代码在运行Kitkat及更低版本的设备上运行良好。但在运行棒棒糖的设备上，这段代码在第一个实例中工作得很好。但从下一个实例来看，无论我是断开连接还是关闭连接并重试，它都不起作用。在onConnectionStateChange方法中，它一直给我一个257的状态码。据我所知，对于kitkat和Lollipop设备，蓝牙GATT方法是相同的。

让我惊讶的是，当我使用旧的BLE API时，这个代码在棒棒糖设备上运行得很好，即startLeScan (用于eg - mBluetoothAdapter.startLeScan(mLeScanCallback);)。只有当我使用新的BLE，即BluetoothLeScanner ( scanner.startScan(filters, settings, new scancallback());)时，才会出现这个问题。使用旧的BLE API的棒棒糖设备的扫描速度真的很慢，因此我无法使用它。我只是不明白如何解决这个problem.Has，有没有人遇到同样的问题，找到了解决方案？任何帮助都将深表感谢。

Answer 1

这里有相当多的东西我需要修改。为您要从特征中读取的数据创建一个类变量，如私有字符串heartRate；

1)您不需要readCharacteristic()方法。相反，一旦设备正确连接，就应该在onConnectionStateChange中调用mBluetoothGatt.discoverServices()。然后，在onServicesDiscovered()方法中，我将调用gatt.getServices()。然后使用foreach循环遍历返回的服务，比较服务的UUID，直到找到您关心的服务。如果heartRate ==为空，则调用service.getCharacteristic(HeartRateUUID)，然后读取特征。在onCharacteristicRead()中，检查UUID是否等于心率特征。如果是，则将特征的值赋给heartRate变量。如果您感兴趣，我可以输入方法或提供伪代码。

2)我不会调用后面跟着gatt.discoverServices()的gatt.connect()。一旦看到来自当前设备的通告数据包，gatt.connect()将立即重新连接到该设备。我会先调用gatt.connect()，然后在onConnectedStateChange()方法中调用gatt.discoverServices()。

3)在onConnectedStateChange方法中，不要使用gatt变量。请改用mBluetoothGatt。mBluetoothGatt.disconnect()与当前连接的设备断开连接。mBluetoothGatt.close()终止gatt实例。在调用mBluetoothGatt.Close()之后，不能调用mBluetoothGatt.connect()。这可能不是必需的，但如果设备已连接，我将调用mBluetoothGatt.disconnect()，然后调用mBluetoothGatt.close()。

4)您还可以将特征读数链接在一起。在onCharacteristicRead()中，在获得heartRate的值之后，可以立即调用characteristic.getService().getCharacteristic(UUIDTemperature)，然后读取该特征。它将再次调用OnCharacteristicRead方法。

如果你想要我澄清什么，请告诉我；我正在糟糕的Surface Pro 3键盘上打字。:)