In this section we will send a cloud-to-device message. Upon receiving it, the IoT device will perform an action:

1. Send a cloud-to-device message from a cloud solution to an IoT device:

ServiceClient serviceClient;
serviceClient = ServiceClient.CreateFromConnectionString(abc.GetConnectionString());

abc.SendCloudToDeviceMessageAsync(deviceId, serviceClient);

2. Prepare and send messages:

var commandMessage = new Message(Encoding.ASCII.GetBytes("Close=100"));
 await serviceClient.SendAsync(deviceId, commandMessage);

3. The IoT device will reply by sending an acknowledgement message:

 while (true)
 {
 Message receivedMessage = await deviceClient.ReceiveAsync();
 if (receivedMessage == null) continue;

 var cmdMessage = Encoding.ASCII.GetString(receivedMessage.GetBytes());

 // take acttion based on cmdMessage value
 // ..... Some code here .....

 //Send Ack to IoT Hub
 await deviceClient.CompleteAsync(receivedMessage);
 }

4. The IoT solution will process the feedback acknowledgement:

var feedbackReceiver = serviceClient.GetFeedbackReceiver();

while (true)
{
 var feedbackBatch = await feedbackReceiver.ReceiveAsync();
 if (feedbackBatch == null) continue;
 
 // take action & Udate database for action taken 
 foreach (var feedback in feedbackBatch.Records)
 {
 if (feedback.StatusCode != FeedbackStatusCode.Success)
 {
 // Handle compensation here
 }
 }

 await feedbackReceiver.CompleteAsync(feedbackBatch);
}