1. Import the required classes and interfaces.

   import net.rim.blackberry.api.bbm.platform.*;
   import net.rim.blackberry.api.bbm.platform.service.*;
   import net.rim.device.api.ui.component.*;

2. Create a class that extends MainScreen. In the constructor for this screen class, pass in the application's associated BBMPlatformContext.

   public class MyBBMInviteScreen extends MainScreen
   {
       public MyBBMInviteScreen(BBMPlatformContext platformContext)
       {
   
       }
   }

3. In the MyBBMInviteScreen constructor, retrieve a reference to the messaging service associated with this application's platform context.

   public class MyBBMInviteScreen extends MainScreen
   {
       public MyBBMInviteScreen(BBMPlatformContext platformContext)
       {
           MessagingService messagingService = platformContext.getMessagingService();
       }
   }

4. Define a channel listener. The code sample in step 5 assumes that you named the listener class, MyChannelListener.
5. Invoke MessagingService.createChannel() to create a new BBMPlatformChannel, passing in your channel listener class.

   public class MyBBMInviteScreen extends MainScreen
   {
       public MyBBMInviteScreen(BBMPlatformContext platformContext)
       {
           MessagingService messagingService = platformContext.getMessagingService();
           BBMPlatformChannel channel = messagingService.createChannel(new MyChannelListener());
       }
   }

6. In an if statement that checks whether you created the BBMPlatformChannel successfully, invoke BBMPlatformChannel.sendInvitation() to invite a contact to your application. In the parameters for sendInvitation(), you can specify a message to be displayed when the contact receives the invitation, a parameter that will be passed to the application's main method as args[1], and an expiry time. The following code sample passes in the value 0 for expiry time (that is, the invitation never expires). A Contact picker UI component opens for the user to choose a contact to invite.

   public class MyBBMInviteScreen extends MainScreen
   {
       public MyBBMInviteScreen(BBMPlatformContext platformContext)
       {
           MessagingService messagingService = platformContext.getMessagingService();
           BBMPlatformChannel channel = messagingService.createChannel(new MyChannelListener());
           
           if (channel != null) 
           {
               channel.sendInvitation(“Let's play a game”, "Chess App", 0);
           }
       }
   }

You can interact with the contact that you invited to your channel when they accept your invitation.

Code sample: Sending a join invitation to a contact

import net.rim.blackberry.api.bbm.platform.*;
import net.rim.blackberry.api.bbm.platform.service.*;
import net.rim.device.api.ui.component.*;

public class MyBBMInviteScreen extends MainScreen
{
    public MyBBMInviteScreen(BBMPlatformContext platformContext)
    {
        MessagingService messagingService = platformContext.getMessagingService();
       
        BBMPlatformChannel channel = messagingService.createChannel(new MyChannelListener());

        if (channel != null) 
        {
            channel.sendInvitation(“Let's play a game”, "Chess App", 0);
        }
    }
}