The code below works if the device is online and offline wtihin minutes. However, when it is offline more than 1 hour, and is switched to online, the SetConnectionStatusChangesHandler's handler is not invoked.
public class IotHubService
{
Microsoft.Azure.Devices.Client.DeviceClient _deviceClient;
public void InitDeviceClient()
{
_deviceClient = DeviceClient.Create(_iotHubEndpoint,
new DeviceAuthenticationWithToken(deviceId, sasToken),
TransportType.Mqtt_WebSocket_Only);
var retryPolicy = new MyExponentialBackOff(...);
_deviceClient.SetRetryPolicy(retryPolicy);
// Set handlers and callbacks
_deviceClient.SetConnectionStatusChangesHandler(ConnectionStatusChanged);
_iotHubCancellationTokenSource = new CancellationTokenSource();
await _deviceClient.OpenAsync(_iotHubCancellationTokenSource.Token);
}
//this does NOT get invoked if the device is offline for more than one hour, and switched to online
public async void ConnectionStatusChanged(ConnectionStatus status, ConnectionStatusChangeReason reason)
{
}
}
public class MyExponentialBackOff : IRetryPolicy
{
public bool ShouldRetry(int currentRetryCount, Exception lastException, out TimeSpan retryInterval)
{
if (currentRetryCount < _retryCount) //_retryCounty is int.MaxValue
{
retryInterval = TimeSpan.FromMilliseconds(10000);
return true;
}
retryInterval = TimeSpan.Zero;
return false;
}
}
Microsoft.Azure.Devices.Client: Version="1.21.0"
Xamarin Android Lollipop
