安卓Ble蓝牙如何设置characteristic里面value值变化

[jmHeart]

按照谷歌官方的demo 。 这样设置 characteristic，为何接受不到数据，onCharacteristicChanged 没有回调
/**
* Enables or disables notification on a give characteristic.
*
* @param characteristic Characteristic to act on.
* @param enabled If true, enable notification. False otherwise.
*/
public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,
boolean enabled) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
// This is specific to Heart Rate Measurement.
if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {

BluetoothGattDescriptor descriptor = characteristic.getDescriptor(UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));

descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);

mBluetoothGatt.writeDescriptor(descriptor);
}
}
求指导，怎么设置 characteristic ，通知

[霸气觉醒]

我也没办法收到通知，楼主最后怎么解决的呀？能告知一下吗？谢谢