RFCommConnectionTrigger in Windows Universal Apps To detect Incoming Bluetooth Connection - bluetooth

Question

I am working on a Windows Universal App. I Want to get the Data from a Bluetooth Device to the Windows Phone. I am Using the Concept of RFCommCommunicationTrigger for this Purpose.
Here's the code Snippet I am Using
var rfTrigger = new RfcommConnectionTrigger();
// Specify what the service ID is
rfTrigger.InboundConnection.LocalServiceId = RfcommServiceId.FromUuid(new Guid("<some_base_guid>"));
//Register RFComm trigger
var rfReg = RegisterTaskOnce(
"HWRFCommTrigger",
"BackgroundLibrary.RFBackgroundTask",
rfTrigger, null
);
SetCompletedOnce(rfReg, OnTaskCompleted);
Here the Function of RegisterTaskOnce
static private IBackgroundTaskRegistration RegisterTaskOnce(string taskName, string entryPoint, IBackgroundTrigger trigger, params IBackgroundCondition[] conditions)
{
// Validate
if (string.IsNullOrEmpty(taskName)) throw new ArgumentException("taskName");
if (string.IsNullOrEmpty(entryPoint)) throw new ArgumentException("entryPoint");
if (trigger == null) throw new ArgumentNullException("trigger");
// Look to see if the name is already registered
var existingReg = (from reg in BackgroundTaskRegistration.AllTasks
where reg.Value.Name == taskName
select reg.Value).FirstOrDefault();
Debug.WriteLine("Background task "+ taskName+" is already running in the Background");
// If already registered, just return the existing registration
if (existingReg != null)
{
return existingReg;
}
// Create the builder
var builder = new BackgroundTaskBuilder();
builder.TaskEntryPoint = entryPoint;
builder.Name = taskName;
builder.SetTrigger(trigger);
// Conditions?
if (conditions != null)
{
foreach (var condition in conditions)
{
builder.AddCondition(condition);
}
}
// Register
return builder.Register();
}
Here's the code for SetCompletedOnce this will add a Handler only once
static private void SetCompletedOnce(IBackgroundTaskRegistration reg, BackgroundTaskCompletedEventHandler handler)
{
// Validate
if (reg == null) throw new ArgumentNullException("reg");
if (handler == null) throw new ArgumentNullException("handler");
// Unsubscribe in case already subscribed
reg.Completed -= handler;
// Subscribe
reg.Completed += handler;
}
I have also Written the BackgroundLibrary.RFBackgroundTask.cs
public sealed class RFBackgroundTask : IBackgroundTask
{
public async void Run(IBackgroundTaskInstance taskInstance)
{
BackgroundTaskDeferral deferral = taskInstance.GetDeferral();
try
{
Debug.WriteLine(taskInstance.TriggerDetails.GetType());
taskInstance.Canceled += new BackgroundTaskCanceledEventHandler(OnCanceled);
Debug.WriteLine("RFComm Task Running");
Debug.WriteLine(taskInstance.TriggerDetails.GetType().ToString());
}
catch (System.Exception e)
{
Debug.WriteLine("RFComm Task Error: {0}", e.Message);
}
deferral.Complete();
}
}
The Run Method is Invoked Every Time The Device tries to Open the Connection.
The type of the Trigger that is obtained (the type I am debugging in the run method of the RFBackgroundTask.cs) is printed as
Windows.Devices.Bluetooth.Background.RfcommConnectionTriggerDetails
But I am Unable use that because I dont have this Class in the BackgroundLibrary project.
The Documentation says that this Provides information about the Bluetooth device that caused this trigger to fire.
It has Variables like Socket,RemoteDevice etc.
I think I am Missing something very simple
Can you please help me out .

Answer 1

Once your background task is launched, simply cast the TriggerDetails object to an RfcommConnectionTriggerDetails object:
public sealed class RFBackgroundTask : IBackgroundTask
{
public async void Run(IBackgroundTaskInstance taskInstance)
{
BackgroundTaskDeferral deferral = taskInstance.GetDeferral();
try
{
taskInstance.Canceled += new BackgroundTaskCanceledEventHandler(OnCanceled);
RfcommConnectionTriggerDetails details = (RfcommConnectionTriggerDetails)taskInstance.TriggerDetails;
StreamSocket = details.Socket; // Rfcomm Socket
// Access other properties...
}
catch (System.Exception e)
{
Debug.WriteLine("RFComm Task Error: {0}", e.Message);
}
deferral.Complete();
}
}