How to use InvokeDeviceMethod csharp

Question

I want to know how to use the InvokeDeviceMethod from the azure-sdk for C# on GitHub, in which I make requests to a simulator programmed with C++, and it returns a JSON response. I'm using Windows Forms and I want to display it on a graphical interface.

Answer 1

The sample uses the C# service SDK. The first important step is to connect to your IoT hub using a connection string you passed in from the command line:

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

The sample then calls the InvokeMethodAsync method. This async method creates a CloudToDeviceMethod instance to call the SetTelemetryInterval method on your device. The device ID is also passed in as a parameter to the sample:

// Invoke the direct method on the device, passing the payload.
        private static async Task InvokeMethodAsync(string deviceId, ServiceClient serviceClient)
        {
            var methodInvocation = new CloudToDeviceMethod("SetTelemetryInterval")
            {
                ResponseTimeout = TimeSpan.FromSeconds(30),
            };
            methodInvocation.SetPayloadJson("10");

            Console.WriteLine($"Invoking direct method for device: {deviceId}");

            // Invoke the direct method asynchronously and get the response from the simulated device.
            CloudToDeviceMethodResult response = await serviceClient.InvokeDeviceMethodAsync(deviceId, methodInvocation);

            Console.WriteLine($"Response status: {response.Status}, payload:\n\t{response.GetPayloadAsJson()}");

        }

You can find a detailed walk through here: https://learn.microsoft.com/azure/iot-hub/quickstart-control-device?pivots=programming-language-csharp