Querying a Feature Set Dynamically Using CFeatureDiscovery

How to query a feature set using CFeatureDiscovery dynamically.

1. 
   Decide the set of features you want to query and determine their Uids,
2. 
   create an instance of TFeatureSet,

   
     // Dynamic way of using multiple feature query. This is preferred
     // way to fetch support statuses if there are several features to be 
     // queried, because it involves less inter-process communication.
     TFeatureSet featset;
   

3. 
   add each feature you want to query by calling the Append() function of TFeatureSet with the Uid of the feature as argument (one call for each feature),

   
     User::LeaveIfError( featset.Append( <featureUIDx> ) );
     User::LeaveIfError( featset.Append( <featureUIDx> ) );
   

4. 
   create an instance of CFeatureDiscovery,

   
     // Call NewLC() to create an instance of CFeatureDiscovery.
     // The method leaves the instance of the object on the cleanup stack.
     CFeatureDiscovery* testB = CFeatureDiscovery::NewLC();
   

5. 
   call its FeaturesSupported() function with the TFeatureSet as argument, and

   
     // Call the exported IsSupported() method to query whether features 
     // are supported in the current environment or not. 
     TBool wcdmaSupported = testB->IsSupported(<featureUIDx>);
     TBool gsmSupported = testB->IsSupported(<featureUIDx>);
   

6. 
   destroy the CFeatureDiscovery instance when you have finished with it if it was created with NewL() rather than NewLC().