Run the example

  1. Install and run the device gateway
  2. Download the C# client library
  3. Copy the root certificate of the device gateway to your working directory. As default, the certificate(ca.crt) resides in cert of the installation directory.
  4. The example uses grpc-dotnet. You can change the example/event/test/test.csproj file as needed.

  5. Change the gateway and the device information in example/event/test/Program.cs as needed.

     // the path of the root certificate
 private const string GATEWAY_CA_FILE = "../../../../cert/gateway/ca.crt";

 // the address of the gateway
 private const string GATEWAY_ADDR = "192.168.0.2";
 private const int GATEWAY_PORT = 4000;

 // the ip address of the target device
 private const string DEVICE_ADDR = "192.168.0.110";
 private const int DEVICE_PORT = 51211;

  6. Build and run.

     cd example/event/test
 dotnet run

1. Connect to the gateway and the device

The example assumes you use the device gateway. For the master gateway or other connection options, refer to the Connect or ConnectMaster examples.

  GatewayClient gatewayClient = new GatewayClient();
  gatewayClient.Connect(GATEWAY_CA_FILE, GATEWAY_ADDR, GATEWAY_PORT);

  var connectInfo = new ConnectInfo{ IPAddr = DEVICE_ADDR, Port = DEVICE_PORT, UseSSL = USE_SSL };
  uint devID = userTest.connectSvc.Connect(connectInfo);

2. Initialize the event code map

Since V1.3, the event code map, event_code.json, is provided. You can use it in your application for looking up the short descriptions of event codes.

  public void InitCodeMap(string filename) {
    var jsonData = File.ReadAllText(filename);
    codeMap = JsonSerializer.Deserialize<EventCodeMap>(jsonData);
  }

  public string GetEventString(uint eventCode, uint subCode) {
    for(int i = 0; i < codeMap.entries.Count; i++) {
      if(eventCode == codeMap.entries[i].event_code && subCode == codeMap.entries[i].sub_code) {
        return codeMap.entries[i].desc;
      }
    }

    return string.Format("Unknown event(0x{0:X})", eventCode | subCode);
  }

  eventSvc.InitCodeMap(CODE_MAP_FILE);

3. Receive realtime events

To receive realtime events from the devices, you have to do the followings.

  1. Enable monitoring on target devices.
  2. Subscribe to the event channel.
  3. Read the events from the channel.
  static async void ReceiveEvents(EventSvc svc, IAsyncStreamReader<EventLog> stream, CancellationToken token) {
    try {
      while(await stream.MoveNext(token)) {
        var eventLog = stream.Current;

        // do something with the event
      }
    }
  }   

  var enableRequest = new EnableMonitoringRequest{ DeviceID = deviceID };
  eventClient.EnableMonitoring(enableRequest);

  var subscribeRequest = new SubscribeRealtimeLogRequest{ DeviceIDs = {deviceID}, QueueSize = MONITORING_QUEUE_SIZE };
  var call = eventClient.SubscribeRealtimeLog(subscribeRequest);

  cancellationTokenSource = new CancellationTokenSource();

  ReceiveEvents(this, call.ResponseStream, cancellationTokenSource.Token);

4. Read event logs

When reading event logs, you can specify the starting index and the maximum number of events.

  var events = eventSvc.GetLog(deviceID, firstEventID, MAX_NUM_EVENT);

  for(int i = 0; i < events.Count; i++) {
    PrintEvent(events[i]);
  }

Updated: