Question

我需要从我的Raspberry中安装的Universal App向Azure Iot Hub（https://azure.microsoft.com/it-it/services/iot-hub/）发送消息。我使用HTTP协议是因为Raspberry不支持AMQP。我使用以下代码：

public sealed partial class MainPage : Page
{
    private DispatcherTimer _timer = null;
    private DeviceClient _deviceClient = null;
    private const string _deviceConnectionString = "<myConnectionString>";

    public MainPage()
    {
        InitializeComponent();

        _deviceClient = DeviceClient.CreateFromConnectionString(_deviceConnectionString, TransportType.Http1);

        _timer = new DispatcherTimer();
        _timer.Interval = TimeSpan.FromSeconds(5);
        _timer.Tick += _timer_Tick;
        _timer.Start();
    }

    private async void _timer_Tick(object sender, object e)
    {
        string msg = "{deviceId: 'myFirstDevice', timestamp: " + DateTime.Now.Ticks + " }";

        Message eventMessage = new Message(Encoding.UTF8.GetBytes(msg));
        await _deviceClient.SendEventAsync(eventMessage);
    }
}

SendEventAsync给了我：

Exception thrown: 'Microsoft.Azure.Devices.Client.Exceptions.IotHubCommunicationException' in mscorlib.ni.dll

Message: {"An error occurred while sending the request."}

我已列入我的项目Microsoft.AspNet.WebApi.Client，如此处所示：https://github.com/Azure/azure-iot-sdks/issues/65没有结果。

"dependencies": {
    "Microsoft.AspNet.WebApi.Client": "5.2.3",
    "Microsoft.Azure.Devices.Client": "1.0.0-preview-007",
    "Microsoft.NETCore.UniversalWindowsPlatform": "5.0.0"
 },
"frameworks": {
    "uap10.0": {}
}

如果我在控制台应用程序中尝试SAME代码，它会按预期工作。

Answer 1

@danvy是对的，你需要生成一个SAS令牌，这里有一个签名生成器https://github.com/sandrinodimattia/RedDog/releases

可能有多种方式发送事件，您正在使用http，请查看此示例

// Generate a SAS key with the Signature Generator.: 
var sas = "SharedAccessSignature sr=https%3a%2f%2freddogeventhub.servicebus.windows.net%2ftemperature%2fpublishers%2flivingroom%2fmessages&sig=I7n%2bqlIExBRs23V4mcYYfYVYhc6adOlMAeTY9VM9kNg%3d&se=1405562228&skn=SenderDevice";

// Namespace info.
var serviceNamespace = "myeventhub";  
var hubName = "temperature";  
var deviceName = "livingroom";

// Create client.
var httpClient = new HttpClient();  
httpClient.BaseAddress =  
           new Uri(String.Format("https://{0}.servicebus.windows.net/", serviceNamespace));
httpClient.DefaultRequestHeaders  
           .TryAddWithoutValidation("Authorization", sas);

Console.WriteLine("Starting device: {0}", deviceName);

// Keep sending.
while (true)  
{
    var eventData = new
    {
        Temperature = new Random().Next(20, 50)
    };

    var postResult = httpClient.PostAsJsonAsync(
           String.Format("{0}/publishers/{1}/messages", hubName, deviceName), eventData).Result;

    Console.WriteLine("Sent temperature using HttpClient: {0}", 
           eventData.Temperature);
    Console.WriteLine(" > Response: {0}", 
           postResult.StatusCode);
    Console.WriteLine(" > Response Content: {0}", 
           postResult.Content.ReadAsStringAsync().Result);

    Thread.Sleep(new Random().Next(1000, 5000));
}

查看此文章了解更多详情http://fabriccontroller.net/iot-with-azure-service-bus-event-hubs-authenticating-and-sending-from-any-type-of-device-net-and-js-samples/

Answer 2

尝试使用本教程

为您的设备设置连接字符串（_deviceConnectionString）

https://github.com/Azure/azure-iot-sdks/blob/master/tools/DeviceExplorer/doc/how_to_use_device_explorer.md

您可以直接使用从IoT Hub获取的信息或从IoT Suite向导创建的仪表板手动执行此操作。它看起来像这样

_deviceConnectionString =“HostName = YourIoTHubName.azure-devices.net; DeviceId = YourDeviceId; SharedAccessKey = YourDeviceSharedAccessKey”;

Answer 3

您是否使用CreateDeviceIdentity工具正确生成了DeviceId和设备密钥？以下是指南：https://blogs.windows.com/buildingapps/2015/12/09/windows-iot-core-and-azure-iot-hub-putting-the-i-in-iot/

Answer 4

经过数小时的搜索，我发现了一个硬件问题。我的Raspberry试图使用未配置的Wi-Fi加密狗发送请求，而所有其他请求都使用网络电缆。移除加密狗就可以了。

从Raspberry向Azure Iot Hub发送消息

4 个答案: