如何实时查看来自 Azure IoT 中心的设备遥测消息？

Question

我正在尝试创建一个与 Azure IoT 浏览器设备遥测页面基本相同的应用程序。

我想实时读取设备发送的设备到云消息。

这是我当前使用的代码，它不会返回任何消息，我所看到的是为分区 0 和 1 启动了两个线程。

连接字符串是直接从 Azure IoT 中心网页复制的。

XXX 班{

    EventHubConsumerClient eventHubConsumerClient;
    private const string ConsumerGroup = "$Default";

    private async Task Setup()
    {
        eventHubConsumerClient = new EventHubConsumerClient(ConsumerGroup, eventHubConnectionString);
        cancellationSource = new CancellationTokenSource();
        var tasks = new List<Task>();
        var partitions = await eventHubConsumerClient.GetPartitionIdsAsync();
        foreach (string partition in partitions)
        {
            tasks.Add(ReceiveMessagesFromDeviceAsync(partition, cancellationSource));
        }
    }

    async Task ReceiveMessagesFromDeviceAsync(string partitionId, CancellationTokenSource cs)
    {
        Telemetry.Add($"Starting listener thread for partition: {partitionId}");
        try
        {
            while (IsTelemetryStarted)
            {
                await foreach (PartitionEvent receivedEvent in eventHubConsumerClient.ReadEventsFromPartitionAsync(partitionId, EventPosition.Latest, cs.Token))
                {
                    string msgSource;
                    string body = Encoding.UTF8.GetString(receivedEvent.Data.Body.ToArray());
                    if (receivedEvent.Data.SystemProperties.ContainsKey("iothub-message-source"))
                    {
                        msgSource = receivedEvent.Data.SystemProperties["iothub-message-source"].ToString();
                        Debug.WriteLine($"{partitionId} {msgSource} {body}");
                        Telemetry.Add($"{partitionId} {msgSource} {body}");
                    }
                }
            }
        } catch( Exception ex )
        {

        }
        Telemetry.Add($"Stopped listener thread for partition: {partitionId}.");
    }
}

Answer 1

您的代码示例不完整，因此无法判断发生了什么。该类不完整，没有可调用的方法。什么是

Telemetry

？

Setup()

方法创建一些永远不会等待的任务，它也不会返回任务列表。

这可行，也许从这里开始并从那里开始。

await using var consumerClient = new EventHubConsumerClient(EventHubConsumerClient.DefaultConsumerGroupName, "redacted");

await foreach (PartitionEvent partitionEvent in consumerClient.ReadEventsAsync())
{
    string readData = System.Text.Encoding.UTF8.GetString(partitionEvent.Data.Body.ToArray());
    Console.WriteLine($"Read event of length {readData.Length} from partition {partitionEvent.Partition.PartitionId}");
    Console.WriteLine($"Message: {readData}");
}