java - BluetoothGatt.writeCharacteristic 一半时间返回 false

Question

实际上我是通过蓝牙进行更新的。第一次我删除存储体，然后在上面写入一个十六进制文件。

但是有一半的时间更新无法正常工作，对于我传输的每个数据，第一个 writeCharacteristic 将返回 false。它有一半的时间发生在整个更新中。

我在 Debug模式下尝试，但在这种情况下该方法永远不会返回 false，当然这可能是延迟问题，但我无法增加时间。

这是我发送数据的代码:

public void sendTX(final byte[] sMessage) {
        BluetoothGattService service = mBluetoothGatt.getService(UUID_SERVICE_SERIAL);
        if (service != null && sMessage != null) {
            Log.d(TAG,"sMessage : " + sMessage);

            final BluetoothGattCharacteristic characteristic = service.getCharacteristic(UUID_TX);
            if (characteristic != null) {

                Thread thread = new Thread() {
                    public void run() {

                        if (sMessage.length > 20) {

                            for (int i = 0; i < sMessage.length; i += 20) {
                                byte[] byteArraySplit = Arrays.copyOfRange(sMessage, i, i + 20 < sMessage.length ? i + 20 : sMessage.length);
                                characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
                                characteristic.setValue(byteArraySplit);
                                while(!mBluetoothGatt.writeCharacteristic(characteristic)) {
                                    try {
                                        TimeUnit.MILLISECONDS.sleep(15);
                                    } catch (InterruptedException e) {
                                        e.printStackTrace();
                                    }
                                 }
                            }
                        } else {
                            characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
                            characteristic.setValue(sMessage);
                            while(!mBluetoothGatt.writeCharacteristic(characteristic)){

                            try {
                                 TimeUnit.MILLISECONDS.sleep(15);
                               } catch (InterruptedException e) {
                                 e.printStackTrace();
                              }

                            }

                        }

                    }
                };
                thread.start();
            } else {
                Log.d(TAG, "UUID TX null");

            }
        } else {
            Log.d(TAG, "Service BLE null");
        }
    }

这是 native writeCharacteristic 方法的代码:

public boolean writeCharacteristic(BluetoothGattCharacteristic characteristic) {
        if ((characteristic.getProperties() & BluetoothGattCharacteristic.PROPERTY_WRITE) == 0
            && (characteristic.getProperties() &
                BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE) == 0) return false;

        if (VDBG) Log.d(TAG, "writeCharacteristic() - uuid: " + characteristic.getUuid());
        if (mService == null || mClientIf == 0 || characteristic.getValue() == null) return false;

        BluetoothGattService service = characteristic.getService();
        if (service == null) return false;

        BluetoothDevice device = service.getDevice();
        if (device == null) return false;

        synchronized(mDeviceBusy) {
            if (mDeviceBusy) return false;
            mDeviceBusy = true;
        }

        try {
            mService.writeCharacteristic(mClientIf, device.getAddress(),
                characteristic.getInstanceId(), characteristic.getWriteType(),
                AUTHENTICATION_NONE, characteristic.getValue());
        } catch (RemoteException e) {
            Log.e(TAG,"",e);
            mDeviceBusy = false;
            return false;
        }

        return true;
    }

Answer 1

切勿使用超时来尝试解决此问题。正确的做法是等待回调，然后执行下一个请求。请参阅Android BLE BluetoothGatt.writeDescriptor() return sometimes false .