我只需要使用适用于 node.js 的 Azure 设备 sdk 获取设备的双胞胎。我确实使用了如下客户端代码:-
import { Client } from 'azure-iot-device';
import { Mqtt } from 'azure-iot-device-mqtt';
await client.setOptions(options);
await client.open();
const twin = await client.getTwin();
问题是返回的双胞胎没有设备双胞胎字段,但其他字段如下:-
{
_events: [Object: null prototype] { newListener: [Function: bound ] },
_eventsCount: 1,
_maxListeners: undefined,
_transport: Mqtt {
_events: [Object: null prototype] {
error: [Function],
connected: [Function],
disconnect: [Array],
message: [Function],
twinDesiredPropertiesUpdate: [Function: bound ]
},
_eventsCount: 5,
_maxListeners: undefined,
_mid: '',
_firstConnection: false,
_authenticationProvider: X509AuthenticationProvider { type: 0, _credentials: [Object] },
_mqtt: MqttBase {
_events: [Object: null prototype],
_eventsCount: 2,
_maxListeners: undefined,
mqttProvider: [Object],
_onTheWirePublishes: [OnTheWireMessageContainer],
_fsm: [constructor],
_options: [Object],
_config: [Object],
_mqttClient: [MqttClient],
[Symbol(kCapture)]: false
},
_twinClient: MqttTwinClient {
_events: [Object: null prototype],
_eventsCount: 1,
_maxListeners: undefined,
_pendingTwinRequests: {},
_mqtt: [MqttBase],
_topicFsm: [BehavioralFsm],
_responseTopic: [Object],
_desiredPropertiesUpdatesTopic: [Object],
[Symbol(kCapture)]: false
},
_fsm: constructor {
initialState: 'disconnected',
states: [Object],
eventListeners: [Object],
namespace: 'fsm.2',
useSafeEmit: false,
hierarchy: {},
pendingDelegations: {},
_stamped: true,
inputQueue: [],
targetReplayState: 'connected',
state: 'connected',
priorState: 'connecting',
priorAction: 'connected.getTwin',
currentAction: '',
currentActionArgs: undefined,
inExitHandler: false
},
_topicTelemetryPublish: 'devices/amidha/messages/events/',
_topics: { method: [Object], message: [Object] },
_userAgentString: 'azure-iot-device/1.17.1 (node v12.18.0; Ubuntu 18.04; x64)',
[Symbol(kCapture)]: false
},
_retryPolicy: ExponentialBackOffWithJitter {
_errorFilter: DefaultErrorFilter {
ArgumentError: false,
ArgumentOutOfRangeError: false,
DeviceMaximumQueueDepthExceededError: false,
DeviceNotFoundError: false,
FormatError: false,
UnauthorizedError: false,
NotImplementedError: false,
NotConnectedError: true,
IotHubQuotaExceededError: false,
MessageTooLargeError: false,
InternalServerError: true,
ServiceUnavailableError: true,
IotHubNotFoundError: false,
IoTHubSuspendedError: false,
JobNotFoundError: false,
TooManyDevicesError: false,
ThrottlingError: true,
DeviceAlreadyExistsError: false,
DeviceMessageLockLostError: false,
InvalidEtagError: false,
InvalidOperationError: false,
PreconditionFailedError: false,
TimeoutError: true,
BadDeviceResponseError: false,
GatewayTimeoutError: false,
DeviceTimeoutError: false,
TwinRequestError: false
},
immediateFirstRetry: true,
normalParameters: ExponentialBackoffWithJitterParameters {
c: 100,
cMin: 100,
cMax: 10000,
ju: 0.25,
jd: 0.5
},
throttledParameters: ExponentialBackoffWithJitterParameters {
c: 5000,
cMin: 10000,
cMax: 60000,
ju: 0.25,
jd: 0.5
}
},
_maxOperationTimeout: 240000,
desiredPropertiesUpdatesEnabled: false,
properties: {
reported: { update: [Function: update], '$version': 1 },
desired: { '$version': 1 }
},
[Symbol(kCapture)]: false
}
我不想听我可以通过使用上述对象轻松完成的孪生更改事件twin.on
。我只需要获取设备的当前双胞胎。是否可以?