IoT 隨插即用服務開發人員指南

發行項
02/06/2024

IoT 隨插即用可讓您建置IoT裝置，向Azure IoT應用程式公告其功能。當客戶將裝置連線到啟用 IoT 隨插即用的應用程式時，IoT 隨插即用裝置不需要手動設定。

IoT 隨插即用可讓您使用已向IoT中樞宣告其模型標識碼的裝置。例如，您可以直接存取裝置的屬性和命令。

如果您使用IoT Central，您可以使用IoT Central UI和 REST API 來與連線至應用程式的 IoT 隨插即用裝置互動。

服務 SDK

在您的解決方案中使用 Azure IoT 服務 SDK 來與裝置和模組互動。例如，您可以使用服務 SDK 來讀取和更新對應項屬性，以及叫用命令。支持的語言包括 C#、Java、Node.js 和 Python。

Azure IoT 服務 SDK 包含程式代碼，可協助建置直接與 IoT 中樞互動的應用程式，以管理裝置和安全性。

平台	套件	程式碼存放庫	範例	參考
.NET	NuGet (英文)	GitHub	範例	參考
Java	Maven	GitHub	範例	參考
節點	npm \(英文\)	GitHub	範例	參考
Python	匹普	GitHub	範例	參考

服務 SDK 可讓您從解決方案元件存取裝置資訊，例如桌面或 Web 應用程式。服務 SDK 包含兩個命名空間和物件模型，可用來擷取模型識別碼：

IoT 中樞服務用戶端。此服務會將模型標識元公開為裝置對應項屬性。
Digital Twins 用戶端。新的 Digital Twins API 會在 Digital Twins 定義語言（DTDL）模型建構上運作，例如元件、屬性和命令。 Digital Twin API 可讓解決方案產生器更輕鬆地建立 IoT 隨插即用解決方案。

您也可以使用下列資源：

IoT 中樞服務用戶端範例

本節說明使用 IoT 中樞服務用戶端和 RegistryManager 和 ServiceClient 類別的 C# 範例。您可以使用 RegistryManager 類別，使用裝置對應項與裝置狀態互動。您也可以使用 RegistryManager 類別來查詢 IoT 中樞中的裝置註冊。您可以使用 ServiceClient 類別來呼叫裝置上的命令。裝置的 DTDL 模型會定義裝置所實作的屬性和命令。在代碼段中，deviceTwinId變數會保存向IoT中樞註冊之 IoT 隨插即用裝置的裝置識別碼。

取得裝置對應項和型號標識碼

若要取得連線至IoT中樞之 IoT 隨插即用裝置的裝置對應項和型號標識碼：

RegistryManager registryManager = RegistryManager.CreateFromConnectionString(parameters.HubConnectionString);

Twin twin = await registryManager.GetTwinAsync(deviceTwinId);
Console.WriteLine($"Device twin: \n{JsonConvert.SerializeObject(twin, Formatting.Indented)}");
Console.WriteLine($"Model ID: {twin.ModelId}.");

更新裝置對應項

下列代碼段示範如何更新 targetTemperature 裝置上的屬性。此範例示範如何在更新對應項之前取得對應項 ETag 。屬性定義於裝置的預設元件中：

Twin twin = await registryManager.GetTwinAsync(deviceTwinId);

int desiredTargetTemperature = 60;

// Update the twin
var twinPatch = new Twin();
twinPatch.Properties.Desired["targetTemperature"] = desiredTargetTemperature;

Console.WriteLine($"Update the targetTemperature property to {desiredTargetTemperature}.");

await registryManager.UpdateTwinAsync(deviceTwinId, twinPatch, twin.ETag);

下列代碼段示範如何更新 targetTemperature 元件上的屬性。此範例示範如何在更新對應項之前取得對應項 ETag 。屬性定義於 Thermostat1 元件中：

Twin twin = await registryManager.GetTwinAsync(deviceTwinId);

int desiredTargetTemperature = 60;

var twinPatch = CreatePropertyPatch("targetTemperature", desiredTargetTemperature, "thermostat1");

await registryManager.UpdateTwinAsync(deviceTwinId, twinPatch, twin.ETag);

// ...

private static Twin CreatePropertyPatch(string propertyName, object propertyValue, string componentName)
{
    var twinPatch = new Twin();
    twinPatch.Properties.Desired[componentName] = new
    {
        __t = "c"
    };
    twinPatch.Properties.Desired[componentName][propertyName] = JsonConvert.SerializeObject(propertyValue);
    return twinPatch;
}

對於元件中的屬性，屬性修補程式看起來像下列範例：

{
"sampleComponentName":
  {
    "__t": "c",
    "samplePropertyName": 20
  }
}

呼叫命令

下列代碼段示範如何叫 getMaxMinReport 用預設元件中定義的命令：

ServiceClient serviceClient = ServiceClient.CreateFromConnectionString(parameters.HubConnectionString);

var commandInvocation = new CloudToDeviceMethod("getMaxMinReport") { ResponseTimeout = TimeSpan.FromSeconds(30) };

// Set command payload
DateTimeOffset since = DateTimeOffset.Now.Subtract(TimeSpan.FromMinutes(2));
string componentCommandPayload = JsonConvert.SerializeObject(since);
commandInvocation.SetPayloadJson(componentCommandPayload);

try
{
  CloudToDeviceMethodResult result = await serviceClient.InvokeDeviceMethodAsync(deviceTwinId, commandInvocation);

  Console.WriteLine($"Command getMaxMinReport was invoked." +
      $"\nDevice returned status: {result.Status}. \nReport: {result.GetPayloadAsJson()}");
}
catch (DeviceNotFoundException)
{
    Console.WriteLine($"Unable to execute command getMaxMinReport on {deviceTwinId}.";
}

下列代碼段示範如何在元件上呼叫 getMaxMinReport 命令。這個指令定義於 Thermostat1 元件中：

// Create command name to invoke for component. The command is formatted as <component name>*<command name>
string commandToInvoke = "thermostat1*getMaxMinReport";
var commandInvocation = new CloudToDeviceMethod(commandToInvoke) { ResponseTimeout = TimeSpan.FromSeconds(30) };

// Set command payload
DateTimeOffset since = DateTimeOffset.Now.Subtract(TimeSpan.FromMinutes(2));
string componentCommandPayload = JsonConvert.SerializeObject(since);
commandInvocation.SetPayloadJson(componentCommandPayload);

try
{
    CloudToDeviceMethodResult result = await serviceClient.InvokeDeviceMethodAsync(deviceTwinId, commandInvocation);
    Console.WriteLine($"Command getMaxMinReport was invoked on component thermostat1." +
        $"\nDevice returned status: {result.Status}. \nReport: {result.GetPayloadAsJson()}");
}
catch (DeviceNotFoundException)
{
    Console.WriteLine("Unable to execute command getMaxMinReport on component thermostat1.");
}

IoT 中樞數字對應項範例

您可以使用 DigitalTwinClient 類別，使用數位對應項與裝置狀態互動。裝置的 DTDL 模型會定義裝置所實作的屬性和命令。

本節說明使用 Digital Twins API 的 C# 範例。下列代碼段會使用下列類別來代表控溫器和溫度控制器裝置的數字對應項目：

using Microsoft.Azure.Devices.Serialization;
using Newtonsoft.Json;
using System;

namespace Microsoft.Azure.Devices.Samples
{
  internal class ThermostatTwin : BasicDigitalTwin
  {
    [JsonProperty("$metadata")]
    public new ThermostatMetadata Metadata { get; set; }

    [JsonProperty("maxTempSinceLastReboot")]
    public double? MaxTempSinceLastReboot { get; set; }

    [JsonProperty("targetTemperature")]
    public double? TargetTemperature { get; set; }
  }

  internal class ThermostatMetadata : DigitalTwinMetadata
  {
    [JsonProperty("maxTempSinceLastReboot")]
    public ReportedPropertyMetadata MaxTempSinceLastReboot { get; set; }

    [JsonProperty("targetTemperature")]
    public WritableProperty TargetTemperature { get; set; }
  }

  internal class ReportedPropertyMetadata
  {
    [JsonProperty("lastUpdateTime")]
    public DateTimeOffset LastUpdateTime { get; set; }
  }

  internal class TemperatureControllerTwin : BasicDigitalTwin
  {
    [JsonProperty("$metadata")]
    public new TemperatureControllerMetadata Metadata { get; set; }

    [JsonProperty("serialNumber")]
    public string SerialNumber { get; set; }

    [JsonProperty("thermostat1")]
    public ThermostatTwin Thermostat1 { get; set; }

    [JsonProperty("thermostat2")]
    public ThermostatTwin Thermostat2 { get; set; }
  }

  internal class TemperatureControllerMetadata : DigitalTwinMetadata
  {
    [JsonProperty("serialNumber")]
    public ReportedPropertyMetadata SerialNumber { get; set; }

    [JsonProperty("thermostat1")]
    public WritableProperty Thermostat1 { get; set; }

    [JsonProperty("thermostat2")]
    public WritableProperty Thermostat2 { get; set; }
  }
}

digitalTwinId變數會保存向IoT中樞註冊之 IoT 隨插即用裝置的裝置標識碼。

取得數字對應項和模型標識碼

若要取得連線至IoT中樞之 IoT 隨插即用裝置的數字對應項和模型標識碼：

DigitalTwinClient digitalTwinClient = DigitalTwinClient.CreateFromConnectionString(parameters.HubConnectionString);
HttpOperationResponse<ThermostatTwin, DigitalTwinGetHeaders> getDigitalTwinResponse = await digitalTwinClient
    .GetDigitalTwinAsync<ThermostatTwin>(digitalTwinId);
ThermostatTwin thermostatTwin = getDigitalTwinResponse.Body;
Console.WriteLine($"Model ID: {thermostatTwin.Metadata.ModelId}.");
Console.WriteLine($"Digital Twin: \n{JsonConvert.SerializeObject(thermostatTwin, Formatting.Indented)}");

更新數字對應項

下列代碼段示範如何更新 targetTemperature 裝置上的屬性。屬性定義於裝置的預設元件中：

var updateOperation = new UpdateOperationsUtility();

int desiredTargetTemperature = 60;

// Get the current value of the targetTemperature property
HttpOperationResponse<ThermostatTwin, DigitalTwinGetHeaders> getDigitalTwinResponse = await digitalTwinClient
    .GetDigitalTwinAsync<ThermostatTwin>(digitalTwinId);
double? currentTargetTemperature = getDigitalTwinResponse.Body.TargetTemperature;

// Has the targetTemperature property previously been set?
if (currentTargetTemperature != null)
{
  // Update the existing property
  // Prepend the property path with a '/'
  updateOperation.AppendReplacePropertyOp($"/targetTemperature",   desiredTargetTemperature);
}
else
{
  // Add a new property
  // Prepend the property path with a '/'
  updateOperation.AppendAddPropertyOp($"/targetTemperature", desiredTargetTemperature);
}

// Update the targetTemperature property on the digital twin
HttpOperationHeaderResponse<DigitalTwinUpdateHeaders> updateDigitalTwinResponse = await digitalTwinClient
    .UpdateDigitalTwinAsync(digitalTwinId, updateOperation.Serialize());

Console.WriteLine($"Update {digitalTwinId} digital twin response: {updateDigitalTwinResponse.Response.StatusCode}.");

下列代碼段示範如何更新 targetTemperature 元件上的屬性。屬性定義於 Thermostat1 元件中：

int desiredTargetTemperature = 60;

var updateOperation = new UpdateOperationsUtility();

// Look at when the property was updated and what was it set to.
HttpOperationResponse<TemperatureControllerTwin, DigitalTwinGetHeaders> getDigitalTwinResponse = await digitalTwinClient
  .GetDigitalTwinAsync<TemperatureControllerTwin>(digitalTwinId);

ThermostatTwin thermostat1 = getDigitalTwinResponse.Body.Thermostat1;

if (thermostat1 != null)
{
  // Thermostat1 is present in the TemperatureController twin. You can add/replace the component-level property "targetTemperature"
  double? currentComponentTargetTemperature = getDigitalTwinResponse.Body.Thermostat1.TargetTemperature;
  if (currentComponentTargetTemperature != null)
  {
      DateTimeOffset targetTemperatureDesiredLastUpdateTime = getDigitalTwinResponse.Body.Thermostat1.Metadata.TargetTemperature.LastUpdateTime;

      // The property path to be replaced should be prepended with a '/'
      updateOperation.AppendReplacePropertyOp("/thermostat1/targetTemperature", desiredTargetTemperature);
  }
  else
  {
      // The property path to be added should be prepended with a '/'
      updateOperation.AppendAddPropertyOp("/thermostat1/targetTemperature", desiredTargetTemperature);
  }
}
else
{
    // Thermostat1 is not present in the TemperatureController twin. Add the component.
    var componentProperty = new Dictionary<string, object> { { "targetTemperature", desiredTargetTemperature }, { "$metadata", new object() } };

    // The property path to be replaced should be prepended with a '/'
    updateOperation.AppendAddComponentOp("/thermostat1", componentProperty);
}

HttpOperationHeaderResponse<DigitalTwinUpdateHeaders> updateDigitalTwinResponse = await digitalTwinClient
    .UpdateDigitalTwinAsync(digitalTwinId, updateOperation.Serialize());

Console.WriteLine($"Update {digitalTwinId} digital twin response: {updateDigitalTwinResponse.Response.StatusCode}.");

呼叫命令

下列代碼段示範如何叫 getMaxMinReport 用預設元件中定義的命令：

DateTimeOffset since = DateTimeOffset.Now.Subtract(TimeSpan.FromMinutes(2));

try
{
  HttpOperationResponse<DigitalTwinCommandResponse, DigitalTwinInvokeCommandHeaders> invokeCommandResponse = await digitalTwinClient
    .InvokeCommandAsync(digitalTwinId, "getMaxMinReport", JsonConvert.SerializeObject(since));

  Console.WriteLine($"Command getMaxMinReport was invoked. \nDevice returned status: {invokeCommandResponse.Body.Status}." +
    $"\nReport: {invokeCommandResponse.Body.Payload}");
}
catch (HttpOperationException e)
{
  if (e.Response.StatusCode == HttpStatusCode.NotFound)
  {
    Console.WriteLine($"Unable to execute command getMaxMinReport on {digitalTwinId}.");
  }
}

下列代碼段示範如何在元件上呼叫 getMaxMinReport 命令。這個指令定義於 Thermostat1 元件中：

DateTimeOffset since = DateTimeOffset.Now.Subtract(TimeSpan.FromMinutes(2));

try
{
    HttpOperationResponse<DigitalTwinCommandResponse, DigitalTwinInvokeCommandHeaders> invokeCommandResponse = await digitalTwinClient
        .InvokeComponentCommandAsync(digitalTwinId, "thermostat1", "getMaxMinReport", JsonConvert.SerializeObject(since));

    Console.WriteLine("Command getMaxMinReport was invoked on component thermostat1." +
        $"\nDevice returned status: {invokeCommandResponse.Body.Status}. \nReport: {invokeCommandResponse.Body.Payload}");
}
catch (HttpOperationException e)
{
    if (e.Response.StatusCode == HttpStatusCode.NotFound)
    {
        Console.WriteLine("Unable to execute command getMaxMinReport on component thermostat1.");
    }
}

讀取裝置遙測

IoT 隨插即用裝置會將 DTDL 模型中定義的遙測傳送至 IoT 中樞。根據預設，IoT 中樞將遙測路由傳送至事件中樞端點，您可以在其中取用遙測。若要深入瞭解，請參閱使用 IoT 中樞訊息路由將裝置到雲端訊息傳送至不同的端點。

下列代碼段示範如何從預設事件中樞端點讀取遙測。此代碼段中的程式代碼取自 IoT 中樞快速入門：將遙測從裝置傳送至 IoT 中樞，並使用後端應用程式加以讀取：

await using EventHubConsumerClient consumer = new EventHubConsumerClient(EventHubConsumerClient.DefaultConsumerGroupName, connectionString, EventHubName);

Console.WriteLine("Listening for messages on all partitions");

try
{
    await foreach (PartitionEvent partitionEvent in consumer.ReadEventsAsync(cancellationToken))
    {
        Console.WriteLine("Message received on partition {0}:", partitionEvent.Partition.PartitionId);

        string data = Encoding.UTF8.GetString(partitionEvent.Data.Body.ToArray());
        Console.WriteLine("\t{0}:", data);

        Console.WriteLine("Application properties (set by device):");
        foreach (var prop in partitionEvent.Data.Properties)
        {
            Console.WriteLine("\t{0}: {1}", prop.Key, prop.Value);
        }

        Console.WriteLine("System properties (set by IoT Hub):");
        foreach (var prop in partitionEvent.Data.SystemProperties)
        {
            Console.WriteLine("\t{0}: {1}", prop.Key, prop.Value);
        }
    }
}
catch (TaskCanceledException)
{
    // This is expected when the token is signaled; it should not be considered an
    // error in this scenario.
}

下列來自上一個程式代碼的輸出會顯示只有預設元件的無元件控溫器 IoT 隨插即用裝置所傳送的溫度遙測。 dt-dataschema系統屬性會顯示模型識別碼：

Message received on partition 1:
        { "temperature": 25.5 }:
Application properties (set by device):
System properties (set by IoT Hub):
        iothub-connection-device-id: my-pnp-device
        iothub-connection-auth-method: {"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}
        iothub-connection-auth-generation-id: 637375045610235418
        iothub-enqueuedtime: 05/10/2020 14:30:58
        iothub-message-source: Telemetry
        dt-dataschema: dtmi:com:example:Thermostat;1
        content-type: application/json
        content-encoding: utf-8

上一個程式代碼的下列輸出會顯示多元件 TemperatureController IoT 隨插即用裝置所傳送的溫度遙測。系統 dt-subject 屬性會顯示傳送遙測之元件的名稱。在此範例中，這兩個元件是 thermostat1thermostat2 和，如 DTDL 模型中所定義。 dt-dataschema系統屬性會顯示模型識別碼：

Message received on partition 1:
        {"temperature":11.1}:
Application properties (set by device):
System properties (set by IoT Hub):
        dt-subject: thermostat1
        iothub-connection-device-id: my-pnp-device
        iothub-connection-auth-method: {"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}
        iothub-connection-auth-generation-id: 637375045610235418
        iothub-enqueuedtime: 05/10/2020 14:23:36
        iothub-message-source: Telemetry
        dt-dataschema: dtmi:com:example:TemperatureController;1
        content-type: application/json
        content-encoding: utf-8
Message received on partition 1:
        {"temperature":41.2}:
Application properties (set by device):
System properties (set by IoT Hub):
        dt-subject: thermostat2
        iothub-connection-device-id: my-pnp-device
        iothub-connection-auth-method: {"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}
        iothub-connection-auth-generation-id: 637375045610235418
        iothub-enqueuedtime: 05/10/2020 14:23:36
        iothub-message-source: Telemetry
        dt-dataschema: dtmi:com:example:TemperatureController;1
        content-type: application/json
        content-encoding: utf-8

讀取裝置對應項變更通知

您可以設定 IoT 中樞來產生裝置對應項變更通知，以路由傳送至支援的端點。若要深入瞭解，請參閱使用 IoT 中樞訊息路由將裝置到雲端訊息傳送至不同的端點>非遙測事件。

當 IoT 中樞產生無元件控溫器裝置的裝置對應項變更通知時，上一個 C# 代碼段中顯示的程式代碼會產生下列輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Message received on partition 1:
        {"version":3,"properties":{"reported":{"maxTempSinceLastReboot":9.6,"$metadata":{"$lastUpdated":"2020-10-06T10:17:41.7408552Z","maxTempSinceLastReboot":{"$lastUpdated":"2020-10-06T10:17:41.7408552Z"}},"$version":2}}}:
Application properties (set by device):
        hubName: my-pnp-hub
        deviceId: my-pnp-device
        operationTimestamp: 2020-10-06T10:17:41.7408552+00:00
        iothub-message-schema: twinChangeNotification
        opType: updateTwin
System properties (set by IoT Hub):
        iothub-connection-device-id: my-pnp-device
        iothub-enqueuedtime: 06/10/2020 10:17:41
        iothub-message-source: twinChangeEvents
        user-id: System.ArraySegment`1[System.Byte]
        correlation-id: 61394e8ba7d
        content-type: application/json
        content-encoding: utf-8

當 IoT 中樞產生具有元件之裝置的裝置對應項變更通知時，上一個 C# 代碼段中顯示的程式代碼會產生下列輸出。此範例顯示當具有控溫器元件的溫度感測器裝置產生通知時，輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Message received on partition 1:
        {"version":5,"properties":{"reported":{"thermostat1":{"__t":"c","maxTempSinceLastReboot":9.6},"$metadata":{"$lastUpdated":"2020-10-06T10:27:59.515972Z","thermostat1":{"$lastUpdated":"2020-10-06T10:27:59.515972Z","__t":{"$lastUpdated":"2020-10-06T10:27:59.515972Z"},"maxTempSinceLastReboot":{"$lastUpdated":"2020-10-06T10:27:59.515972Z"}}},"$version":4}}}:
Application properties (set by device):
        hubName: my-pnp-hub
        deviceId: my-pnp-device
        operationTimestamp: 2020-10-06T10:27:59.5159720+00:00
        iothub-message-schema: twinChangeNotification
        opType: updateTwin
System properties (set by IoT Hub):
        iothub-connection-device-id: my-pnp-device
        iothub-enqueuedtime: 06/10/2020 10:27:59
        iothub-message-source: twinChangeEvents
        user-id: System.ArraySegment`1[System.Byte]
        correlation-id: 615051f364e
        content-type: application/json
        content-encoding: utf-8

讀取數字對應項變更通知

您可以設定 IoT 中樞來產生數字對應項變更通知，以路由傳送至支援的端點。若要深入瞭解，請參閱使用 IoT 中樞訊息路由將裝置到雲端訊息傳送至不同的端點>非遙測事件。

當 IoT 中樞產生無元件控溫器裝置的數字對應項變更通知時，上一個 C# 代碼段中顯示的程式代碼會產生下列輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Message received on partition 1:
        [{"op":"add","path":"/$metadata/maxTempSinceLastReboot","value":{"lastUpdateTime":"2020-10-06T10:39:16.0209836Z"}},{"op":"add","path":"/maxTempSinceLastReboot","value":34.9}]:
Application properties (set by device):
        hubName: my-pnp-hub
        deviceId: my-pnp-device
        operationTimestamp: 2020-10-06T10:39:16.0209836+00:00
        iothub-message-schema: digitalTwinChangeNotification
        opType: updateTwin
System properties (set by IoT Hub):
        iothub-connection-device-id: my-pnp-device
        iothub-enqueuedtime: 06/10/2020 10:39:16
        iothub-message-source: digitalTwinChangeEvents
        user-id: System.ArraySegment`1[System.Byte]
        correlation-id: 6169857bf8c
        content-type: application/json-patch+json
        content-encoding: utf-8

在 IoT 中樞為具有元件之裝置產生數字對應項變更通知時，上一個 C# 代碼段中顯示的程式代碼會產生下列輸出。此範例顯示當具有控溫器元件的溫度感測器裝置產生通知時，輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Message received on partition 1:
        [{"op":"add","path":"/thermostat1","value":{"$metadata":{"maxTempSinceLastReboot":{"lastUpdateTime":"2020-10-06T10:41:44.8312666Z"}},"maxTempSinceLastReboot":29.1}}]:
Application properties (set by device):
        hubName: my-pnp-hub
        deviceId: my-pnp-device
        operationTimestamp: 2020-10-06T10:41:44.8312666+00:00
        iothub-message-schema: digitalTwinChangeNotification
        opType: updateTwin
System properties (set by IoT Hub):
        iothub-connection-device-id: my-pnp-device
        iothub-enqueuedtime: 06/10/2020 10:41:44
        iothub-message-source: digitalTwinChangeEvents
        user-id: System.ArraySegment`1[System.Byte]
        correlation-id: 616f108f0e3
        content-type: application/json-patch+json
        content-encoding: utf-8

您也可以使用下列資源：

IoT 中樞服務用戶端範例

本節說明使用 com.microsoft.azure.sdk.iot.service.devicetwin 命名空間中的 IoT 中樞服務用戶端和 DeviceTwin 和 DeviceMethod 類別的 Java 範例。您可以使用 DeviceTwin 類別，使用裝置對應項與裝置狀態互動。您也可以使用 DeviceTwin 類別來查詢 IoT 中樞中的裝置註冊。您可以使用 DeviceMethod 類別來呼叫裝置上的命令。裝置的 DTDL 模型會定義裝置所實作的屬性和命令。在代碼段中，deviceId變數會保存向IoT中樞註冊之 IoT 隨插即用裝置的裝置識別碼。

取得裝置對應項和型號標識碼

若要取得連線至IoT中樞之 IoT 隨插即用裝置的裝置對應項和型號標識碼：

DeviceTwin twinClient = DeviceTwin.createFromConnectionString(iotHubConnectionString);

// ...

DeviceTwinDevice twin = new DeviceTwinDevice(deviceId);
twinClient.getTwin(twin);
System.out.println("Model Id of this Twin is: " + twin.getModelId());

更新裝置對應項

下列代碼段示範如何更新 targetTemperature 裝置上的屬性。您必須先取得對應項，才能進行更新。屬性定義於裝置的預設元件中：

DeviceTwin twinClient = DeviceTwin.createFromConnectionString(iotHubConnectionString);
DeviceTwinDevice twin = new DeviceTwinDevice(deviceId);
twinClient.getTwin(twin);

double propertyValue = 60.2;
twin.setDesiredProperties(Collections.singleton(new Pair("targetTemperature", propertyValue)));
twinClient.updateTwin(twin);

下列代碼段示範如何更新 targetTemperature 元件上的屬性。您必須先取得對應項，才能進行更新。屬性定義於控溫器1元件中：

public static Set<Pair> CreateComponentPropertyPatch(@NonNull String propertyName, @NonNull double propertyValue, @NonNull String componentName)
{
    JsonObject patchJson = new JsonObject();
    patchJson.addProperty("__t", "c");
    patchJson.addProperty(propertyName, propertyValue);
    return singleton(new Pair(componentName, patchJson));
}

// ...

DeviceTwin twinClient = DeviceTwin.createFromConnectionString(iotHubConnectionString);
DeviceTwinDevice twin = new DeviceTwinDevice(deviceId);
twinClient.getTwin(twin);

double propertyValue = 60.2;
twin.setDesiredProperties(CreateComponentPropertyPatch("targetTemperature", propertyValue, "thermostat1"));
twinClient.updateTwin(twin);

對於元件中的屬性，屬性修補程式看起來像下列範例：

{
  "thermostat1":
  {
    "__t": "c",
    "targetTemperature": 60.2
  }
}

呼叫命令

下列代碼段示範如何叫 getMaxMinReport 用預設元件中定義的命令：

DeviceMethod methodClient = DeviceMethod.createFromConnectionString(iotHubConnectionString);

Long responseTimeout = TimeUnit.SECONDS.toSeconds(200);
Long connectTimeout = TimeUnit.SECONDS.toSeconds(5);

String commandInput = ZonedDateTime.now(ZoneOffset.UTC).minusMinutes(5).format(DateTimeFormatter.ISO_DATE_TIME);
MethodResult result = methodClient.invoke(deviceId, "getMaxMinReport", responseTimeout, connectTimeout, commandInput);

System.out.println("Method result status is: " + result.getStatus());

下列代碼段示範如何在元件上呼叫 getMaxMinReport 命令。命令定義於控溫器1元件中：

DeviceMethod methodClient = DeviceMethod.createFromConnectionString(iotHubConnectionString);

Long responseTimeout = TimeUnit.SECONDS.toSeconds(200);
Long connectTimeout = TimeUnit.SECONDS.toSeconds(5);

String commandInput = ZonedDateTime.now(ZoneOffset.UTC).minusMinutes(5).format(DateTimeFormatter.ISO_DATE_TIME);
MethodResult result = methodClient.invoke(deviceId, "thermostat1*getMaxMinReport", responseTimeout, connectTimeout, commandInput);

System.out.println("Method result status is: " + result.getStatus());

IoT 中樞數字對應項範例

您可以使用 com.microsoft.azure.sdk.iot.service.digitaltwin 命名空間中的 DigitalTwinAsyncClient 類別，使用數字對應項與裝置狀態互動。下列範例也會使用來自相同命名空間的 UpdateOperationUtility 和 BasicDigitalTwin 類別。裝置的 DTDL 模型會定義裝置所實作的屬性和命令。

digitalTwinid變數會保存向IoT中樞註冊之 IoT 隨插即用裝置的裝置標識碼。

取得數字對應項和模型標識碼

若要取得連線至IoT中樞之 IoT 隨插即用裝置的數字對應項和模型標識碼：

DigitalTwinAsyncClient asyncClient = DigitalTwinAsyncClient.createFromConnectionString(iotHubConnectionString);

CountDownLatch latch = new CountDownLatch(1);
asyncClient.getDigitalTwin(digitalTwinid, BasicDigitalTwin.class)
    .subscribe(
        getResponse ->
        {
            System.out.println("Digital Twin Model Id: " + getResponse.getMetadata().getModelId());
            System.out.println("Digital Twin: " + prettyBasicDigitalTwin(getResponse));
            latch.countDown();
        },
        error ->
        {
            System.out.println("Get Digital Twin failed: " + error);
            latch.countDown();
        });

latch.await(10, TimeUnit.SECONDS);

// ...

private static String prettyBasicDigitalTwin(BasicDigitalTwin basicDigitalTwin)
{
    Gson gson = new GsonBuilder().setPrettyPrinting().create();
    return gson.toJson(basicDigitalTwin);
}

更新數字對應項

下列代碼段示範如何更新 targetTemperature 裝置上的屬性。屬性定義於裝置的預設元件中：

DigitalTwinAsyncClient asyncClient = DigitalTwinAsyncClient.createFromConnectionString(iotHubConnectionString);

CountDownLatch latch1 = new CountDownLatch(1);

UpdateOperationUtility updateOperationUtility = new UpdateOperationUtility();

// Add a new property.
updateOperationUtility.appendAddPropertyOperation("/" + "targetTemperature", 35);
asyncClient.updateDigitalTwin(digitalTwinid, updateOperationUtility.getUpdateOperations())
    .subscribe(
        getResponse ->
        {
            System.out.println("Updated Digital Twin");
            latch1.countDown();
        },
        error ->
        {
            System.out.println("Update Digital Twin failed: " + error);
            latch1.countDown();
        });
latch1.await(10, TimeUnit.SECONDS);
GetDigitalTwin();

// Replace an existing property.
CountDownLatch latch2 = new CountDownLatch(1);
updateOperationUtility.appendReplacePropertyOperation("/targetTemperature", 50);
asyncClient.updateDigitalTwin(digitalTwinid, updateOperationUtility.getUpdateOperations())
    .subscribe(
        getResponse ->
        {
            System.out.println("Updated Digital Twin");
            latch2.countDown();
        },
        error ->
        {
            System.out.println("Update Digital Twin failed: " + error);
            latch2.countDown();
        });

latch2.await(10, TimeUnit.SECONDS);
GetDigitalTwin();

下列代碼段示範如何更新 targetTemperature 元件上的屬性。屬性定義於控溫器1元件中：

DigitalTwinClient client = DigitalTwinClient.createFromConnectionString(iotHubConnectionString);

// Get digital twin.
ServiceResponseWithHeaders<String, DigitalTwinGetHeaders> getResponse = client.getDigitalTwinWithResponse(digitalTwinid, String.class);

// Construct the options for conditional update.
DigitalTwinUpdateRequestOptions options = new DigitalTwinUpdateRequestOptions();
options.setIfMatch(getResponse.headers().eTag());

UpdateOperationUtility updateOperationUtility = new UpdateOperationUtility();

Map<String, Object> t1properties = new HashMap<>();
t1properties.put("targetTemperature", 50);
updateOperationUtility.appendReplaceComponentOperation("/thermostat1", t1properties);

digitalTwinUpdateOperations = updateOperationUtility.getUpdateOperations();
updateResponse = client.updateDigitalTwinWithResponse(digitalTwinid, digitalTwinUpdateOperations, options);
System.out.println("Update Digital Twin response status: " + updateResponse.response().message());

getResponse = client.getDigitalTwinWithResponse(digitalTwinid, String.class);

呼叫命令

下列代碼段示範如何叫 getMaxMinReport 用預設元件中定義的命令：

CountDownLatch latch = new CountDownLatch(1);

String commandInput = ZonedDateTime.now(ZoneOffset.UTC).minusMinutes(5).format(DateTimeFormatter.ISO_DATE_TIME);

// Invoke a method on root level.
asyncClient.invokeCommand(digitalTwinid, "getMaxMinReport", commandInput)
    .subscribe(
        response ->
        {
            System.out.println("Invoked Command getMaxMinReport response: " + prettyString(response.getPayload()));
            latch.countDown();
        },
        error ->
        {
            RestException ex = (RestException)error;
            if(ex.response().code() == 404) {
                System.out.println("Invoked Command getMaxMinReport failed: " + error);
            }
            else {
                System.out.println("Ensure the device sample is running for this sample to succeed");
            }
            latch.countDown();
        });

latch.await(10, TimeUnit.SECONDS);

// ...

private static String prettyString(String str)
{
    Gson gson = new Gson();
    Gson gsonBuilder = new GsonBuilder().setPrettyPrinting().create();
    return gsonBuilder.toJson(gson.fromJson(str, Object.class));
}

下列代碼段示範如何在元件上呼叫 getMaxMinReport 命令。命令定義於控溫器1元件中：

DigitalTwinClient client = DigitalTwinClient.createFromConnectionString(iotHubConnectionString);

String commandInput = ZonedDateTime.now(ZoneOffset.UTC).minusMinutes(5).format(DateTimeFormatter.ISO_DATE_TIME);

DigitalTwinInvokeCommandRequestOptions options = new DigitalTwinInvokeCommandRequestOptions();
try {
    ServiceResponseWithHeaders<DigitalTwinCommandResponse, DigitalTwinInvokeCommandHeaders> commandResponse = client.invokeComponentCommandWithResponse(digitalTwinid, "thermostat1", "getMaxMinReport", commandInput, options);
    System.out.println("Command getMaxMinReport, payload: " + prettyString(commandResponse.body().getPayload()));
    System.out.println("Command getMaxMinReport, status: " + commandResponse.body().getStatus());
} catch (RestException ex)
{
    if(ex.response().code() == 404)
    {
        System.out.println("Ensure the device sample is running for this sample to succeed.");
    }
    else
    {
        throw ex;
    }
}

// ...

private static String prettyString(String str)
{
    Gson gson = new Gson();
    Gson gsonBuilder = new GsonBuilder().setPrettyPrinting().create();
    return gsonBuilder.toJson(gson.fromJson(str, Object.class));
}

讀取裝置遙測

import com.azure.messaging.eventhubs.EventHubClientBuilder;
import com.azure.messaging.eventhubs.EventHubConsumerAsyncClient;

// ...

EventHubClientBuilder eventHubClientBuilder = new EventHubClientBuilder()
    .consumerGroup(EventHubClientBuilder.DEFAULT_CONSUMER_GROUP_NAME)
    .connectionString(eventHubCompatibleConnectionString);

try (EventHubConsumerAsyncClient eventHubConsumerAsyncClient = eventHubClientBuilder.buildAsyncConsumerClient()) {

    receiveFromAllPartitions(eventHubConsumerAsyncClient);

}

// ...

private static void receiveFromAllPartitions(EventHubConsumerAsyncClient eventHubConsumerAsyncClient) {

eventHubConsumerAsyncClient
    .receive(false) // set this to false to read only the newly available events
    .subscribe(partitionEvent -> {
        System.out.println();
        System.out.printf("%nTelemetry received from partition %s:%n%s",
            partitionEvent.getPartitionContext().getPartitionId(), partitionEvent.getData().getBodyAsString());
        System.out.printf("%nApplication properties (set by device):%n%s", partitionEvent.getData().getProperties());
        System.out.printf("%nSystem properties (set by IoT Hub):%n%s",
            partitionEvent.getData().getSystemProperties());
    }, ex -> {
        System.out.println("Error receiving events " + ex);
    }, () -> {
        System.out.println("Completed receiving events");
    });
}

下列來自上一個程式代碼的輸出會顯示只有預設元件的無元件控溫器 IoT 隨插即用裝置所傳送的溫度遙測。 dt-dataschema系統屬性會顯示模型識別碼：

Telemetry received from partition 1:
{"temperature": 10.700000}
Application properties (set by device):
{$.cdid=my-pnp-device}
System properties (set by IoT Hub):
{correlation-id=dd960185-6ddb-4b5f-89bb-e26b0b3c201e, content-encoding=UTF-8, iothub-connection-auth-method={"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}, iothub-enqueuedtime=Tue Oct 20 12:28:10 BST 2020, dt-dataschema=dtmi:com:example:Thermostat;1, absolute-expiry-time=0, iothub-connection-device-id=my-pnp-device, iothub-connection-auth-generation-id=637375776990653481, group-sequence=0, iothub-message-source=Telemetry, creation-time=0, message-id=1c05cece-070b-4e2e-b2e8-e263858594a3, content-type=application/json}

Telemetry received from partition 1:
{"temperature": 10.700000}
Application properties (set by device):
{$.cdid=my-pnp-device}
System properties (set by IoT Hub):
{correlation-id=d10a7350-43ef-4cf6-9db5-a4b08684cd9d, content-encoding=UTF-8, iothub-connection-auth-method={"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}, iothub-enqueuedtime=Tue Oct 20 12:28:15 BST 2020, dt-dataschema=dtmi:com:example:Thermostat;1, absolute-expiry-time=0, iothub-connection-device-id=my-pnp-device, iothub-connection-auth-generation-id=637375776990653481, group-sequence=0, iothub-message-source=Telemetry, creation-time=0, message-id=d3a80af4-1246-41a0-a09a-582a12c17a00, content-type=application/json}

下列來自上一個程式代碼的輸出會顯示多元件 TemperatureController IoT 隨插即用裝置所傳送的溫度遙測。系統 dt-subject 屬性會顯示傳送遙測之元件的名稱。在此範例中，這兩個元件是 thermostat1thermostat2 和，如 DTDL 模型中所定義。 dt-dataschema系統屬性會顯示模型識別碼：

Telemetry received from partition 1:
null
Application properties (set by device):
{$.cdid=my-pnp-device}
System properties (set by IoT Hub):
{correlation-id=413002d0-2107-4c08-8f4a-995ae1f4047b, content-encoding=UTF-8, iothub-connection-auth-method={"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}, iothub-enqueuedtime=Tue Oct 20 12:31:14 BST 2020, dt-dataschema=dtmi:com:example:TemperatureController;1, absolute-expiry-time=0, iothub-connection-device-id=my-pnp-device, iothub-connection-auth-generation-id=637387902591517456, group-sequence=0, iothub-message-source=Telemetry, creation-time=0, message-id=da8bd068-850e-43fb-862f-66080d5969e4, content-type=application/json, dt-subject=thermostat1}

Telemetry received from partition 1:
null
Application properties (set by device):
{$.cdid=my-pnp-device}
System properties (set by IoT Hub):
{correlation-id=2d9407e5-413f-4f8d-bd30-cd153e03c72f, content-encoding=UTF-8, iothub-connection-auth-method={"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}, iothub-enqueuedtime=Tue Oct 20 12:31:14 BST 2020, dt-dataschema=dtmi:com:example:TemperatureController;1, absolute-expiry-time=0, iothub-connection-device-id=my-pnp-device, iothub-connection-auth-generation-id=637387902591517456, group-sequence=0, iothub-message-source=Telemetry, creation-time=0, message-id=ed419c4e-ef2c-4acf-8991-6245059c5fdc, content-type=application/json, dt-subject=thermostat2}

讀取裝置對應項變更通知

當 IoT 中樞產生無元件控溫器裝置的裝置對應項變更通知時，上一個 Java 代碼段中顯示的程式代碼會產生下列輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Telemetry received from partition 1:
{"version":11,"properties":{"reported":{"maxTempSinceLastReboot":43.4,"$metadata":{"$lastUpdated":"2020-10-20T11:50:41.123127Z","maxTempSinceLastReboot":{"$lastUpdated":"2020-10-20T11:50:41.123127Z"}},"$version":10}}}
Application properties (set by device):
{operationTimestamp=2020-10-20T11:50:41.1231270+00:00, opType=updateTwin, hubName=my-pnp-hub, deviceId=my-pnp-device, iothub-message-schema=twinChangeNotification}
System properties (set by IoT Hub):
{user-id=[B@12fd5bb4, correlation-id=11339418426a, content-encoding=utf-8, iothub-enqueuedtime=Tue Oct 20 12:50:41 BST 2020, absolute-expiry-time=0, iothub-connection-device-id=my-pnp-device, group-sequence=0, iothub-message-source=twinChangeEvents, creation-time=0, content-type=application/json}

當 IoT 中樞產生具有元件之裝置的裝置對應項變更通知時，上一個 Java 代碼段中顯示的程式代碼會產生下列輸出。此範例顯示當具有控溫器元件的溫度感測器裝置產生通知時，輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Telemetry received from partition 1:
{"version":9,"properties":{"reported":{"thermostat1":{"__t":"c","maxTempSinceLastReboot":32.5},"$metadata":{"$lastUpdated":"2020-10-20T11:48:01.2960851Z","thermostat1":{"$lastUpdated":"2020-10-20T11:48:01.2960851Z","__t":{"$lastUpdated":"2020-10-20T11:48:01.2960851Z"},"maxTempSinceLastReboot":{"$lastUpdated":"2020-10-20T11:48:01.2960851Z"}}},"$version":8}}}
Application properties (set by device):
{operationTimestamp=2020-10-20T11:48:01.2960851+00:00, opType=updateTwin, hubName=my-pnp-hub, deviceId=my-pnp-device, iothub-message-schema=twinChangeNotification}
System properties (set by IoT Hub):
{user-id=[B@23949bae, correlation-id=113334d542e1, content-encoding=utf-8, iothub-enqueuedtime=Tue Oct 20 12:48:01 BST 2020, absolute-expiry-time=0, iothub-connection-device-id=my-pnp-device, group-sequence=0, iothub-message-source=twinChangeEvents, creation-time=0, content-type=application/json}

讀取數字對應項變更通知

當 IoT 中樞產生無元件控溫器裝置的數字對應項變更通知時，上一個 Java 代碼段中顯示的程式代碼會產生下列輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Telemetry received from partition 1:
[{"op":"replace","path":"/$metadata/maxTempSinceLastReboot/lastUpdateTime","value":"2020-10-20T11:52:40.627628Z"},{"op":"replace","path":"/maxTempSinceLastReboot","value":16.9}]
Application properties (set by device):
{operationTimestamp=2020-10-20T11:52:40.6276280+00:00, opType=updateTwin, hubName=my-pnp-hub, deviceId=my-pnp-device, iothub-message-schema=digitalTwinChangeNotification}
System properties (set by IoT Hub):
{user-id=[B@4475ce2a, correlation-id=1133db52c0e0, content-encoding=utf-8, iothub-enqueuedtime=Tue Oct 20 12:52:40 BST 2020, absolute-expiry-time=0, iothub-connection-device-id=my-pnp-device, group-sequence=0, iothub-message-source=digitalTwinChangeEvents, creation-time=0, content-type=application/json-patch+json}

當 IoT 中樞為具有元件之裝置產生數字對應項變更通知時，上一個 Java 代碼段中顯示的程式代碼會產生下列輸出。此範例顯示當具有控溫器元件的溫度感測器裝置產生通知時，輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Telemetry received from partition 1:
[{"op":"add","path":"/thermostat1","value":{"$metadata":{"maxTempSinceLastReboot":{"lastUpdateTime":"2020-10-20T11:31:04.7811405Z"}},"maxTempSinceLastReboot":27.2}}]
Application properties (set by device):
{operationTimestamp=2020-10-20T11:31:04.7811405+00:00, opType=updateTwin, hubName=my-pnp-hub, deviceId=my-pnp-device, iothub-message-schema=digitalTwinChangeNotification}
System properties (set by IoT Hub):
{user-id=[B@75981aa, correlation-id=1130d6f4d212, content-encoding=utf-8, iothub-enqueuedtime=Tue Oct 20 12:31:04 BST 2020, absolute-expiry-time=0, iothub-connection-device-id=my-pnp-device, group-sequence=0, iothub-message-source=digitalTwinChangeEvents, creation-time=0, content-type=application/json-patch+json}

您也可以使用下列資源：

IoT 中樞服務用戶端範例

本節說明使用 IoT 中樞服務客戶端和登錄和客戶端類別的 JavaScript 範例。您可以使用 Registry 類別，使用裝置對應項與裝置狀態互動。您也可以使用 Registry 類別來查詢 IoT 中樞中的裝置註冊。您可以使用 Client 類別來呼叫裝置上的命令。裝置的 DTDL 模型會定義裝置所實作的屬性和命令。在代碼段中，deviceId變數會保留向IoT中樞註冊之 IoT 隨插即用裝置的裝置識別碼。

取得裝置對應項和型號標識碼

若要取得連線至IoT中樞之 IoT 隨插即用裝置的裝置對應項和型號標識碼：

var Registry = require('azure-iothub').Registry;

// ...

var registry = Registry.fromConnectionString(connectionString);
registry.getTwin(deviceId, function(err, twin) {
  if (err) {
    console.error(err.message);
  } else {
    console.log('Model Id: ' + twin.modelId);
    console.log(JSON.stringify(twin, null, 2));
  }
}

更新裝置對應項

下列代碼段示範如何更新 targetTemperature 裝置上的屬性。此範例示範如何在更新對應項之前取得對應項。屬性定義於裝置的預設元件中：

var Registry = require('azure-iothub').Registry;
var registry = Registry.fromConnectionString(connectionString);

registry.getTwin(deviceId, function(err, twin) {
  if (err) {
    console.error(err.message);
  } else {
    var twinPatch = {
      properties: {
        desired: {
          targetTemperature: 42
        }
      }
    };
    twin.update(twinPatch, function(err, twin) {
      if (err) {
        console.error(err.message);
      } else {
        console.log(JSON.stringify(twin, null, 2));
      }
    }
  }
}

下列代碼段示範如何更新 targetTemperature 元件上的屬性。此範例示範如何在更新對應項之前取得對應項。屬性定義於控溫器1元件中：

var Registry = require('azure-iothub').Registry;
var registry = Registry.fromConnectionString(connectionString);

registry.getTwin(deviceId, function(err, twin) {
  if (err) {
    console.error(err.message);
  } else {
    var twinPatch = {
      properties: {
        desired: {
          thermostat1:
          {
            __t: "c",
            targetTemperature: 45
          }
        }
      }
    };
    twin.update(twinPatch, function(err, twin) {
      if (err) {
        console.error(err.message);
      } else {
        console.log(JSON.stringify(twin, null, 2));
      }
    }
  }
}

對於元件中的屬性，屬性修補程式看起來像下列範例：

{
  "thermostat1":
  {
    "__t": "c",
    "targetTemperature": 20
  }
}

呼叫命令

下列代碼段示範如何叫 getMaxMinReport 用預設元件中定義的命令：

var Client = require('azure-iothub').Client;

// ...

var client = Client.fromConnectionString(connectionString);

var methodParams = {
  methodName: "getMaxMinReport",
  payload: new Date().getMinutes -2,
  responseTimeoutInSeconds: 15
};

client.invokeDeviceMethod(deviceId, methodParams, function (err, result) {
  if (err) {
    console.error('Failed to invoke method \'' + methodParams.methodName + '\': ' + err.message);
  } else {
    console.log(methodParams.methodName + ' on ' + deviceId + ':');
    console.log(JSON.stringify(result, null, 2));
  }
});

下列代碼段示範如何在元件上呼叫 getMaxMinReport 命令。命令定義於控溫器1元件中：

var Client = require('azure-iothub').Client;

// ...

var client = Client.fromConnectionString(connectionString);

var methodParams = {
  methodName: "thermostat1*getMaxMinReport",
  payload: new Date().getMinutes -2,
  responseTimeoutInSeconds: 15
};

client.invokeDeviceMethod(deviceId, methodParams, function (err, result) {
  if (err) {
    console.error('Failed to invoke method \'' + methodParams.methodName + '\': ' + err.message);
  } else {
    console.log(methodParams.methodName + ' on ' + deviceId + ':');
    console.log(JSON.stringify(result, null, 2));
  }
});

IoT 中樞數字對應項範例

您可以使用 DigitalTwinClient 類別，使用數位對應項與裝置狀態互動。裝置的 DTDL 模型會定義裝置所實作的屬性和命令。

本節說明使用 Digital Twins API 的 JavaScript 範例。

digitalTwinId變數會保存向IoT中樞註冊之 IoT 隨插即用裝置的裝置標識碼。

取得數字對應項和模型標識碼

若要取得連線至IoT中樞之 IoT 隨插即用裝置的數字對應項和模型標識碼：

const IoTHubTokenCredentials = require('azure-iothub').IoTHubTokenCredentials;
const DigitalTwinClient = require('azure-iothub').DigitalTwinClient;
const { inspect } = require('util');

// ...

const credentials = new IoTHubTokenCredentials(connectionString);
const digitalTwinClient = new DigitalTwinClient(credentials);

const digitalTwin = await digitalTwinClient.getDigitalTwin(digitalTwinId);

console.log(inspect(digitalTwin));
console.log('Model Id: ' + inspect(digitalTwin.$metadata.$model));

更新數字對應項

下列代碼段示範如何更新 targetTemperature 裝置上的屬性。屬性定義於裝置的預設元件中：

const IoTHubTokenCredentials = require('azure-iothub').IoTHubTokenCredentials;
const DigitalTwinClient = require('azure-iothub').DigitalTwinClient;

// ...

const credentials = new IoTHubTokenCredentials(connString);
const digitalTwinClient = new DigitalTwinClient(credentials);

const patch = [{
  op: 'add',
  path: '/targetTemperature',
  value: 42
}];
await digitalTwinClient.updateDigitalTwin(digitalTwinId, patch);

下列代碼段示範如何更新 targetTemperature 元件上的屬性。屬性定義於控溫器1元件中：

const IoTHubTokenCredentials = require('azure-iothub').IoTHubTokenCredentials;
const DigitalTwinClient = require('azure-iothub').DigitalTwinClient;

// ...

const credentials = new IoTHubTokenCredentials(connString);
const digitalTwinClient = new DigitalTwinClient(credentials);

const patch = [{
  op: 'add',
  path: '/thermostat1/targetTemperature',
  value: 42
}];
await digitalTwinClient.updateDigitalTwin(digitalTwinId, patch);

呼叫命令

下列代碼段示範如何叫 getMaxMinReport 用預設元件中定義的命令：

const IoTHubTokenCredentials = require('azure-iothub').IoTHubTokenCredentials;
const DigitalTwinClient = require('azure-iothub').DigitalTwinClient;
const { inspect } = require('util');

// ...

const commandPayload = new Date().getMinutes -2;

const credentials = new IoTHubTokenCredentials(connectionString);
const digitalTwinClient = new DigitalTwinClient(credentials);

const options = {
  connectTimeoutInSeconds: 30,
  responseTimeoutInSeconds: 40
};
const commandResponse = await digitalTwinClient.invokeCommand(digitalTwinId, "getMaxMinReport", commandPayload, options);

console.log(inspect(commandResponse));

下列代碼段示範如何在元件上呼叫 getMaxMinReport 命令。命令定義於控溫器1元件中：

const IoTHubTokenCredentials = require('azure-iothub').IoTHubTokenCredentials;
const DigitalTwinClient = require('azure-iothub').DigitalTwinClient;
const { inspect } = require('util');

// ...

const commandPayload = new Date().getMinutes -2;

const credentials = new IoTHubTokenCredentials(connectionString);
const digitalTwinClient = new DigitalTwinClient(credentials);

const options = {
  connectTimeoutInSeconds: 30,
  responseTimeoutInSeconds: 40
};
const commandResponse = await digitalTwinClient.invokeComponentCommand(digitalTwinId, "thermostat1", "getMaxMinReport", commandPayload, options);

console.log(inspect(commandResponse));

讀取裝置遙測

下列代碼段示範如何從預設事件中樞端點讀取遙測。此代碼段中的程式代碼取自 IoT 中樞快速入門：將遙測從裝置傳送至 IoT 中樞，並使用後端應用程式讀取：

const { EventHubConsumerClient } = require("@azure/event-hubs");

var printError = function (err) {
  console.log(err.message);
};

var printMessages = function (messages) {
  for (const message of messages) {
    console.log("Telemetry received: ");
    console.log(JSON.stringify(message.body));
    console.log("Properties (set by device): ");
    console.log(JSON.stringify(message.properties));
    console.log("System properties (set by IoT Hub): ");
    console.log(JSON.stringify(message.systemProperties));
    console.log("");
  }
};

// ...

const clientOptions = {};

const consumerClient = new EventHubConsumerClient("$Default", connectionString, clientOptions);

consumerClient.subscribe({
  processEvents: printMessages,
  processError: printError,
});

Telemetry received:
{"temperature":68.77370855171125}
Properties (set by device):
undefined
System properties (set by IoT Hub):
{"iothub-connection-device-id":"my-pnp-device","iothub-connection-auth-method":"{\"scope\":\"device\",\"type\":\"sas\",\"issuer\":\"iothub\",\"acceptingIpFilterRule\":null}","iothub-connection-auth-generation-id":"637388034455888246","iothub-enqueuedtime":1603206669320,"iothub-message-source":"Telemetry","dt-subject":"thermostat1","dt-dataschema":"dtmi:com:example:TemperatureController;1","contentType":"application/json","contentEncoding":"utf-8"}

Telemetry received:
{"temperature":30.833394506549226}
Properties (set by device):
undefined
System properties (set by IoT Hub):
{"iothub-connection-device-id":"my-pnp-device","iothub-connection-auth-method":"{\"scope\":\"device\",\"type\":\"sas\",\"issuer\":\"iothub\",\"acceptingIpFilterRule\":null}","iothub-connection-auth-generation-id":"637388034455888246","iothub-enqueuedtime":1603206665835,"iothub-message-source":"Telemetry","dt-subject":"thermostat2","dt-dataschema":"dtmi:com:example:TemperatureController;1","contentType":"application/json","contentEncoding":"utf-8"}

讀取裝置對應項變更通知

當 IoT 中樞產生無元件控溫器裝置的裝置對應項變更通知時，上一個 JavaScript 代碼段中顯示的程式代碼會產生下列輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Telemetry received:
{"version":4,"properties":{"reported":{"maxTempSinceLastReboot":42.1415152639582,"$metadata":{"$lastUpdated":"2020-10-21T10:01:40.1281138Z","maxTempSinceLastReboot":{"$lastUpdated":"2020-10-21T10:01:40.1281138Z"}},"$version":3}}}
Properties (set by device):
{"hubName":"my-pnp-hub","deviceId":"my-pnp-device","operationTimestamp":"2020-10-21T10:01:40.1281138+00:00","iothub-message-schema":"twinChangeNotification","opType":"updateTwin"}
System properties (set by IoT Hub):
{"iothub-connection-device-id":"my-pnp-device","iothub-enqueuedtime":1603274500282,"iothub-message-source":"twinChangeEvents","userId":{"type":"Buffer","data":[109,121,45,112,110,112,45,104,117,98]},"correlationId":"11ed82d13f50","contentType":"application/json","contentEncoding":"utf-8"}

當 IoT 中樞產生具有元件之裝置的裝置對應項變更通知時，上一個 JavaScript 代碼段中顯示的程式代碼會產生下列輸出。此範例顯示當具有控溫器元件的溫度感測器裝置產生通知時，輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Telemetry received:
{"version":4,"properties":{"reported":{"thermostat1":{"maxTempSinceLastReboot":3.5592971602417913,"__t":"c"},"$metadata":{"$lastUpdated":"2020-10-21T10:07:51.8284866Z","thermostat1":{"$lastUpdated":"2020-10-21T10:07:51.8284866Z","maxTempSinceLastReboot":{"$lastUpdated":"2020-10-21T10:07:51.8284866Z"},"__t":{"$lastUpdated":"2020-10-21T10:07:51.8284866Z"}}},"$version":3}}}
Properties (set by device):
{"hubName":"my-pnp-hub","deviceId":"my-pnp-device","operationTimestamp":"2020-10-21T10:07:51.8284866+00:00","iothub-message-schema":"twinChangeNotification","opType":"updateTwin"}
System properties (set by IoT Hub):
{"iothub-connection-device-id":"my-pnp-device","iothub-enqueuedtime":1603274871951,"iothub-message-source":"twinChangeEvents","userId":{"type":"Buffer","data":[109,121,45,112,110,112,45,104,117,98]},"correlationId":"11ee605b195f","contentType":"application/json","contentEncoding":"utf-8"}

讀取數字對應項變更通知

在 IoT 中樞為無元件控溫器裝置產生數字對應項變更通知時，上一個 JavaScript 代碼段中顯示的程式代碼會產生下列輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Telemetry received:
[{"op":"add","path":"/$metadata/maxTempSinceLastReboot","value":{"lastUpdateTime":"2020-10-21T10:01:40.1281138Z"}},{"op":"add","path":"/maxTempSinceLastReboot","value":42.1415152639582}]
Properties (set by device):
{"hubName":"my-pnp-hub","deviceId":"my-pnp-device","operationTimestamp":"2020-10-21T10:01:40.1281138+00:00","iothub-message-schema":"digitalTwinChangeNotification","opType":"updateTwin"}
System properties (set by IoT Hub):
{"iothub-connection-device-id":"my-pnp-device","iothub-enqueuedtime":1603274500282,"iothub-message-source":"digitalTwinChangeEvents","userId":{"type":"Buffer","data":[109,121,45,112,110,112,45,104,117,98]},"correlationId":"11ed82d13f50","contentType":"application/json-patch+json","contentEncoding":"utf-8"}

當 IoT 中樞為具有元件之裝置產生數字對應項變更通知時，上一個 JavaScript 代碼段中顯示的程式代碼會產生下列輸出。此範例顯示當具有控溫器元件的溫度感測器裝置產生通知時，輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Telemetry received:
[{"op":"add","path":"/thermostat1","value":{"$metadata":{"maxTempSinceLastReboot":{"lastUpdateTime":"2020-10-21T10:07:51.8284866Z"}},"maxTempSinceLastReboot":3.5592971602417913}}]
Properties (set by device):
{"hubName":"my-pnp-hub","deviceId":"my-pnp-device","operationTimestamp":"2020-10-21T10:07:51.8284866+00:00","iothub-message-schema":"digitalTwinChangeNotification","opType":"updateTwin"}
System properties (set by IoT Hub):
{"iothub-connection-device-id":"my-pnp-device","iothub-enqueuedtime":1603274871951,"iothub-message-source":"digitalTwinChangeEvents","userId":{"type":"Buffer","data":[109,121,45,112,110,112,45,104,117,98]},"correlationId":"11ee605b195f","contentType":"application/json-patch+json","contentEncoding":"utf-8"}

您也可以使用下列資源：

IoT 中樞服務用戶端範例

本節說明使用 IoT 中樞服務用戶端和 IoTHubRegistryManager 和 CloudToDeviceMethod 類別的 Python 範例。您可以使用 IoTHubRegistryManager 類別，使用裝置對應項與裝置狀態互動。您也可以使用IoTHubRegistryManager類別來查詢 IoT 中樞中的裝置註冊。您可以使用 CloudToDeviceMethod 類別來呼叫裝置上的命令。裝置的 DTDL 模型會定義裝置所實作的屬性和命令。在代碼段中，device_id變數會保存向IoT中樞註冊之 IoT 隨插即用裝置的裝置識別碼。

取得裝置對應項和型號標識碼

若要取得連線至IoT中樞之 IoT 隨插即用裝置的裝置對應項和型號標識碼：

from azure.iot.hub import IoTHubRegistryManager
from azure.iot.hub.models import Twin, TwinProperties

iothub_registry_manager = IoTHubRegistryManager(iothub_connection_str)

# ...

twin = iothub_registry_manager.get_twin(device_id)
print("The device twin is: ")
print("")
print(twin)
print("")

additional_props = twin.additional_properties
if "modelId" in additional_props:
    print("The Model ID for this device is:")
    print(additional_props["modelId"])
    print("")

更新裝置對應項

下列代碼段示範如何更新 targetTemperature 裝置上的屬性。此範例示範如何在更新對應項之前取得對應項 etag 。屬性定義於裝置的預設元件中：

iothub_registry_manager = IoTHubRegistryManager(iothub_connection_str)

twin = iothub_registry_manager.get_twin(device_id)

twin_patch = Twin()

twin_patch.properties = TwinProperties(
    desired={"targetTemperature": 42}
)
updated_twin = iothub_registry_manager.update_twin(device_id, twin_patch, twin.etag)

下列代碼段示範如何更新 targetTemperature 元件上的屬性。此範例示範如何在更新對應項之前取得對應項 ETag 。屬性定義於控溫器1元件中：

iothub_registry_manager = IoTHubRegistryManager(iothub_connection_str)

twin = iothub_registry_manager.get_twin(device_id)

twin_patch = Twin()

twin_patch.properties = TwinProperties(
    desired={ "thermostat1": {
        "__t": "c",
        "targetTemperature": 42}
    }
)
updated_twin = iothub_registry_manager.update_twin(device_id, twin_patch, twin.etag)

對於元件中的屬性，屬性修補程式看起來像下列範例：

{
"thermostat1":
  {
    "__t": "c",
    "targetTemperature": 20
  }
}

呼叫命令

下列代碼段示範如何叫 getMaxMinReport 用預設元件中定義的命令：

from azure.iot.hub import IoTHubRegistryManager
from azure.iot.hub.models import CloudToDeviceMethod

# ...

iothub_registry_manager = IoTHubRegistryManager(iothub_connection_str)

method_payload = datetime.datetime.now() - datetime.timedelta(minutes=2)
device_method = CloudToDeviceMethod(method_name="getMaxMinReport", payload=method_payload)
result = iothub_registry_manager.invoke_device_method(device_id, device_method)
print(result.payload)

下列代碼段示範如何在元件上呼叫 getMaxMinReport 命令。命令定義於控溫器1元件中：

from azure.iot.hub import IoTHubRegistryManager
from azure.iot.hub.models import CloudToDeviceMethod

# ...

iothub_registry_manager = IoTHubRegistryManager(iothub_connection_str)

method_payload = datetime.datetime.now() - datetime.timedelta(minutes=2)
device_method = CloudToDeviceMethod(method_name="thermostat1*getMaxMinReport", payload=method_payload)
result = iothub_registry_manager.invoke_device_method(device_id, device_method)
print(result.payload)

IoT 中樞數字對應項範例

您可以使用 DigitalTwinClient 類別，使用數位對應項與裝置狀態互動。裝置的 DTDL 模型會定義裝置所實作的屬性和命令。

device_id變數會保存向IoT中樞註冊之 IoT 隨插即用裝置的裝置標識碼。

取得數字對應項和模型標識碼

若要取得連線至IoT中樞之 IoT 隨插即用裝置的數字對應項和模型標識碼：

from azure.iot.hub import DigitalTwinClient

digital_twin_client = DigitalTwinClient(iothub_connection_str)

digital_twin = digital_twin_client.get_digital_twin(device_id)
if digital_twin:
    print(digital_twin)
    print("Model Id: " + digital_twin["$metadata"]["$model"])
else:
    print("No digital_twin found")

更新數字對應項

下列代碼段示範如何更新 targetTemperature 裝置上的屬性。屬性定義於裝置的預設元件中：

from azure.iot.hub import DigitalTwinClient

digital_twin_client = DigitalTwinClient(iothub_connection_str)

patch = [{"op": "add", "path": "/targetTemperature", "value": 42}]
digital_twin_client.update_digital_twin(device_id, patch)

下列代碼段示範如何更新 targetTemperature 元件上的屬性。屬性定義於控溫器1元件中：

from azure.iot.hub import DigitalTwinClient

digital_twin_client = DigitalTwinClient(iothub_connection_str)

patch = [{"op": "add", "path": "/targetTemperature", "value": 42}]
digital_twin_client.update_digital_twin(device_id, patch)

呼叫命令

下列代碼段示範如何叫 getMaxMinReport 用預設元件中定義的命令：

from azure.iot.hub import DigitalTwinClient

payload = datetime.datetime.now() - datetime.timedelta(minutes=2)

connect_timeout_in_seconds = 3
response_timeout_in_seconds = 7


digital_twin_client = DigitalTwinClient(iothub_connection_str)

invoke_command_result = digital_twin_client.invoke_command(
    device_id, "getMaxMinReport", payload, connect_timeout_in_seconds, response_timeout_in_seconds
)
if invoke_command_result:
    print(invoke_command_result)
else:
    print("No invoke_command_result found")

下列代碼段示範如何在元件上呼叫 getMaxMinReport 命令。命令定義於控溫器1元件中：

from azure.iot.hub import DigitalTwinClient

payload = datetime.datetime.now() - datetime.timedelta(minutes=2)

connect_timeout_in_seconds = 3
response_timeout_in_seconds = 7


digital_twin_client = DigitalTwinClient(iothub_connection_str)

invoke_command_result = digital_twin_client.invoke_component_command(
    device_id, "thermostat1", "getMaxMinReport", payload, connect_timeout_in_seconds, response_timeout_in_seconds
)
if invoke_command_result:
    print(invoke_command_result)
else:
    print("No invoke_command_result found")

讀取裝置遙測

import asyncio
from azure.eventhub import TransportType
from azure.eventhub.aio import EventHubConsumerClient

# Define callbacks to process events
async def on_event_batch(partition_context, events):
    for event in events:
        print("Received event from partition: {}.".format(partition_context.partition_id))
        print("Telemetry received: ", event.body_as_str())
        print("Properties (set by device): ", event.properties)
        print("System properties (set by IoT Hub): ", event.system_properties)
        print()
    await partition_context.update_checkpoint()

async def on_error(partition_context, error):
    # ...

loop = asyncio.get_event_loop()
client = EventHubConsumerClient.from_connection_string(
    conn_str=CONNECTION_STR,
    consumer_group="$default",
)

try:
    loop.run_until_complete(client.receive_batch(on_event_batch=on_event_batch, on_error=on_error))
except KeyboardInterrupt:
    print("Receiving has stopped.")
finally:
    loop.run_until_complete(client.close())
    loop.stop()

下列來自上一個程式代碼的輸出會顯示只有預設元件的無元件控溫器 IoT 隨插即用裝置所傳送的溫度遙測。 dt-dataschema系統屬性會顯示模型識別碼：

Received event from partition: 1.
Telemetry received:  {"temperature": 12}
Properties (set by device):  None
System properties (set by IoT Hub):  {b'content-type': b'application/json', b'content-encoding': b'utf-8', b'iothub-connection-device-id': b'my-pnp-device', b'iothub-connection-auth-method': b'{"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}', b'iothub-connection-auth-generation-id': b'637388855582764406', b'iothub-enqueuedtime': 1603288810715, b'iothub-message-source': b'Telemetry', b'dt-dataschema': b'dtmi:com:example:Thermostat;1', b'x-opt-sequence-number': 13280, b'x-opt-offset': b'12890070640', b'x-opt-enqueued-time': 1603288810824}

Received event from partition: 1.
Telemetry received:  {"temperature": 45}
Properties (set by device):  None
System properties (set by IoT Hub):  {b'content-type': b'application/json', b'content-encoding': b'utf-8', b'iothub-connection-device-id': b'my-pnp-device', b'iothub-connection-auth-method': b'{"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}', b'iothub-connection-auth-generation-id': b'637388858939631652', b'iothub-enqueuedtime': 1603289127844, b'iothub-message-source': b'Telemetry', b'dt-subject': b'thermostat1', b'dt-dataschema': b'dtmi:com:example:TemperatureController;1', b'x-opt-sequence-number': 13328, b'x-opt-offset': b'12890095440', b'x-opt-enqueued-time': 1603289128001}

Received event from partition: 1.
Telemetry received:  {"temperature": 49}
Properties (set by device):  None
System properties (set by IoT Hub):  {b'content-type': b'application/json', b'content-encoding': b'utf-8', b'iothub-connection-device-id': b'my-pnp-device', b'iothub-connection-auth-method': b'{"scope":"device","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}', b'iothub-connection-auth-generation-id': b'637388858939631652', b'iothub-enqueuedtime': 1603289133017, b'iothub-message-source': b'Telemetry', b'dt-subject': b'thermostat2', b'dt-dataschema': b'dtmi:com:example:TemperatureController;1', b'x-opt-sequence-number': 13329, b'x-opt-offset': b'12890095928', b'x-opt-enqueued-time': 1603289133173}

讀取裝置對應項變更通知

當 IoT 中樞產生無元件控溫器裝置的裝置對應項變更通知時，上一個 Python 代碼段中顯示的程式代碼會產生下列輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Received event from partition: 1.
Telemetry received:  {"version":3,"properties":{"reported":{"maxTempSinceLastReboot":10.96,"$metadata":{"$lastUpdated":"2020-10-21T14:10:42.4171263Z","maxTempSinceLastReboot":{"$lastUpdated":"2020-10-21T14:10:42.4171263Z"}},"$version":2}}}
Properties (set by device):  {b'hubName': b'my-pnp-hub', b'deviceId': b'my-pnp-device', b'operationTimestamp': b'2020-10-21T14:10:42.4171263+00:00', b'iothub-message-schema': b'twinChangeNotification', b'opType': b'updateTwin'}
System properties (set by IoT Hub):  {b'user-id': b'my-pnp-hub\x81\x0e\xa4\x7f', b'correlation-id': b'12104ced5402', b'content-type': b'application/json', b'content-encoding': b'utf-8', b'iothub-connection-device-id': b'my-pnp-device', b'iothub-enqueuedtime': 1603289442519, b'iothub-message-source': b'twinChangeEvents', b'x-opt-sequence-number': 13332, b'x-opt-offset': b'12890097392', b'x-opt-enqueued-time': 1603289442738}

當 IoT 中樞產生具有元件之裝置的裝置對應項變更通知時，上一個 Python 代碼段中顯示的程式代碼會產生下列輸出。此範例顯示當具有控溫器元件的溫度感測器裝置產生通知時，輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Received event from partition: 1.
Telemetry received:  {"version":4,"properties":{"reported":{"thermostat1":{"maxTempSinceLastReboot":98.34,"__t":"c"},"$metadata":{"$lastUpdated":"2020-10-21T14:13:39.36491Z","thermostat1":{"$lastUpdated":"2020-10-21T14:13:39.36491Z","maxTempSinceLastReboot":{"$lastUpdated":"2020-10-21T14:13:39.36491Z"},"__t":{"$lastUpdated":"2020-10-21T14:13:39.36491Z"}}},"$version":3}}}
Properties (set by device):  {b'hubName': b'my-pnp-hub', b'deviceId': b'my-pnp-device', b'operationTimestamp': b'2020-10-21T14:13:39.3649100+00:00', b'iothub-message-schema': b'twinChangeNotification', b'opType': b'updateTwin'}
System properties (set by IoT Hub):  {b'user-id': b'my-pnp-hub', b'correlation-id': b'1210b664ab83', b'content-type': b'application/json', b'content-encoding': b'utf-8', b'iothub-connection-device-id': b'my-pnp-device', b'iothub-enqueuedtime': 1603289619481, b'iothub-message-source': b'twinChangeEvents', b'x-opt-sequence-number': 13341, b'x-opt-offset': b'12890102216', b'x-opt-enqueued-time': 1603289619668}

讀取數字對應項變更通知

當 IoT 中樞產生無元件控溫器裝置的數字對應項變更通知時，上一個 Python 代碼段中顯示的程式代碼會產生下列輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Received event from partition: 1.
Telemetry received:  [{"op":"add","path":"/$metadata/maxTempSinceLastReboot","value":{"lastUpdateTime":"2020-10-21T14:10:42.4171263Z"}},{"op":"add","path":"/maxTempSinceLastReboot","value":10.96}]
Properties (set by device):  {b'hubName': b'my-pnp-hub', b'deviceId': b'my-pnp-device', b'operationTimestamp': b'2020-10-21T14:10:42.4171263+00:00', b'iothub-message-schema': b'digitalTwinChangeNotification', b'opType': b'updateTwin'}
System properties (set by IoT Hub):  {b'user-id': b'my-pnp-hub\x81\x0e\xa4\x7f', b'correlation-id': b'12104ced5402', b'content-type': b'application/json-patch+json', b'content-encoding': b'utf-8', b'iothub-connection-device-id': b'my-pnp-device', b'iothub-enqueuedtime': 1603289442519, b'iothub-message-source': b'digitalTwinChangeEvents', b'x-opt-sequence-number': 13333, b'x-opt-offset': b'12890098024', b'x-opt-enqueued-time': 1603289442738}

當 IoT 中樞產生具有元件之裝置的數字對應項變更通知時，上一個 Python 代碼段中顯示的程式代碼會產生下列輸出。此範例顯示當具有控溫器元件的溫度感測器裝置產生通知時，輸出。應用程式屬性 iothub-message-schema ，並提供 opType 變更通知類型的相關信息：

Received event from partition: 1.
Telemetry received:  [{"op":"add","path":"/thermostat1","value":{"$metadata":{"maxTempSinceLastReboot":{"lastUpdateTime":"2020-10-21T14:13:39.36491Z"}},"maxTempSinceLastReboot":98.34}}]
Properties (set by device):  {b'hubName': b'my-pnp-hub', b'deviceId': b'my-pnp-device', b'operationTimestamp': b'2020-10-21T14:13:39.3649100+00:00', b'iothub-message-schema': b'digitalTwinChangeNotification', b'opType': b'updateTwin'}
System properties (set by IoT Hub):  {b'user-id': b'my-pnp-hub', b'correlation-id': b'1210b664ab83', b'content-type': b'application/json-patch+json', b'content-encoding': b'utf-8', b'iothub-connection-device-id': b'my-pnp-device', b'iothub-enqueuedtime': 1603289619481, b'iothub-message-source': b'digitalTwinChangeEvents', b'x-opt-sequence-number': 13342, b'x-opt-offset': b'12890102984', b'x-opt-enqueued-time': 1603289619668}

下一步

既然您已了解裝置模型化，以下是一些更多資源：

IoT 隨插即用 服務開發人員指南

服務 SDK

IoT 中樞 服務用戶端範例

取得裝置對應項和型號標識碼

更新裝置對應項

呼叫命令

IoT 中樞 數字對應項範例

取得數字對應項和模型標識碼

更新數字對應項

呼叫命令

讀取裝置遙測

讀取裝置對應項變更通知

讀取數字對應項變更通知

IoT 中樞 服務用戶端範例

取得裝置對應項和型號標識碼

更新裝置對應項

呼叫命令

IoT 中樞 數字對應項範例

取得數字對應項和模型標識碼

更新數字對應項

呼叫命令

讀取裝置遙測

讀取裝置對應項變更通知

讀取數字對應項變更通知

IoT 中樞 服務用戶端範例

取得裝置對應項和型號標識碼

更新裝置對應項

呼叫命令

IoT 中樞 數字對應項範例

取得數字對應項和模型標識碼

更新數字對應項

呼叫命令

讀取裝置遙測

讀取裝置對應項變更通知

讀取數字對應項變更通知

IoT 中樞 服務用戶端範例

取得裝置對應項和型號標識碼

更新裝置對應項

呼叫命令

IoT 中樞 數字對應項範例

取得數字對應項和模型標識碼

更新數字對應項

呼叫命令

讀取裝置遙測

讀取裝置對應項變更通知

讀取數字對應項變更通知

下一步

其他資源

IoT 隨插即用服務開發人員指南

IoT 中樞服務用戶端範例

IoT 中樞數字對應項範例

IoT 中樞服務用戶端範例

IoT 中樞數字對應項範例

IoT 中樞服務用戶端範例

IoT 中樞數字對應項範例

IoT 中樞服務用戶端範例

IoT 中樞數字對應項範例