public async void Run(IBackgroundTaskInstance taskInstance)
{
backgroundTaskInstance = taskInstance;
// Trigger details contain device id and arguments that are provided by the caller in the main app
// The taskInstance can always be casted to DeviceUseDetails if this background task was started using a DeviceUseTrigger
deviceSyncDetails = (DeviceUseDetails)taskInstance.TriggerDetails;
deferral = taskInstance.GetDeferral();
try
{
backgroundTaskInstance.Progress = 0;
cancellationTokenSource = new CancellationTokenSource();
taskInstance.Canceled += new BackgroundTaskCanceledEventHandler(OnCanceled);
// For simplicity, no error checking will be done after opening the device. Ideally, one should always
// check if the device was successfully opened and respond accordingly. For an example on how to do this,
// please see Scenario 1 of this sample.
//
// The user may also block the device via the settings charm while we are syncing (in background task). In order to deal with
// the user changing permissions, we have to listen for DeviceAccessInformation->AccessChanged events. See EventHandlerForDevice
// for how to handle DeviceAccessInformation.AccessChanged event.
OpenDevice();
// The sample only demonstrates a bulk write for simplicity.
// IO operations can be done after opening the device.
// For more information on BackgroundTasks, please see the BackgroundTask sample on MSDN.
UInt32 bytesWritten = await Task.Run(() =>
{
return(WriteToDeviceAsync());
},
cancellationTokenSource.Token);
ApplicationData.Current.LocalSettings.Values[LocalSettingKeys.SyncBackgroundTaskResult] = bytesWritten;
ApplicationData.Current.LocalSettings.Values[LocalSettingKeys.SyncBackgroundTaskStatus] = BackgroundTaskInformation.TaskCompleted;
}
catch (OperationCanceledException /*ex*/)
{
ApplicationData.Current.LocalSettings.Values[LocalSettingKeys.SyncBackgroundTaskResult] = 0;
ApplicationData.Current.LocalSettings.Values[LocalSettingKeys.SyncBackgroundTaskStatus] = BackgroundTaskInformation.TaskCanceled;
}
finally
{
// Close the device because we are finished syncing and so that the app may reopen the device
device.Dispose();
device = null;
}
// Complete the background task (this raises the OnCompleted event on the corresponding BackgroundTaskRegistration)
deferral.Complete();
}
public async void Run(IBackgroundTaskInstance taskInstance)
{
backgroundTaskInstance = taskInstance;
// Trigger details contain device id and arguments that are provided by the caller in the main app
// The taskInstance can always be casted to DeviceUseDetails if this background task was started using a DeviceUseTrigger
deviceSyncDetails = (DeviceUseDetails)taskInstance.TriggerDetails;
deferral = taskInstance.GetDeferral();
try
{
backgroundTaskInstance.Progress = 0;
cancellationTokenSource = new CancellationTokenSource();
taskInstance.Canceled += new BackgroundTaskCanceledEventHandler(OnCanceled);
// For simplicity, no error checking will be done after opening the device. Ideally, one should always
// check if the device was successfully opened and respond accordingly. For an example on how to do this,
// please see Scenario 1 of this sample.
//
// The user may also block the device via the settings charm while we are syncing (in background task). In order to deal with
// the user changing permissions, we have to listen for DeviceAccessInformation->AccessChanged events. See EventHandlerForDevice
// for how to handle DeviceAccessInformation.AccessChanged event.
OpenDevice();
// The sample only demonstrates a bulk write for simplicity.
// IO operations can be done after opening the device.
// For more information on BackgroundTasks, please see the BackgroundTask sample on MSDN.
UInt32 bytesWritten = await Task.Run(() =>
{
return WriteToDeviceAsync();
},
cancellationTokenSource.Token);
ApplicationData.Current.LocalSettings.Values[LocalSettingKeys.SyncBackgroundTaskResult] = bytesWritten;
ApplicationData.Current.LocalSettings.Values[LocalSettingKeys.SyncBackgroundTaskStatus] = BackgroundTaskInformation.TaskCompleted;
}
catch (OperationCanceledException /*ex*/)
{
ApplicationData.Current.LocalSettings.Values[LocalSettingKeys.SyncBackgroundTaskResult] = 0;
ApplicationData.Current.LocalSettings.Values[LocalSettingKeys.SyncBackgroundTaskStatus] = BackgroundTaskInformation.TaskCanceled;
}
finally
{
// Close the device because we are finished syncing and so that the app may reopen the device
device.Dispose();
device = null;
}
// Complete the background task (this raises the OnCompleted event on the corresponding BackgroundTaskRegistration)
deferral.Complete();
}
private TaskArguments GetTaskArgumentsFromTriggerDetails(DeviceUseDetails details)
{
TaskArguments taskArguments = null;
string argumentsJsonString = details.Arguments;
if (argumentsJsonString != null && argumentsJsonString.Length > 0)
{
taskArguments = JsonConvert.DeserializeObject<TaskArguments>(argumentsJsonString);
}
return taskArguments;
}
