Google Play Game Services's invite dialog doesn't show any friend - c++

Question

I'm trying to get GPG C++'s invitation system to work correctly for an iOS game.
I tried to call RealtimeMultiplayerManager::ShowPlayerSelectUI() to open a dialog to select friends to be invited. However, the dialog doesn't show any friend, only "Auto-Pick" option. I have several Google test accounts in the same circle, and they are already listed as testers in Google Play Console. The game is still in development.
Does anyone know what wrong?
Thanks,
Here is the code:
m_gameServices->RealTimeMultiplayer().ShowPlayerSelectUI(1, 1, true,
[this](gpg::RealTimeMultiplayerManager::PlayerSelectUIResponse const &
response){
HQRemote::Log("inviting friends %d", response.status);
if (gpg::IsError(response.status))
{
handleError((BaseStatus::StatusCode)response.status);
}
else{
auto config = gpg::RealTimeRoomConfig::Builder()
.PopulateFromPlayerSelectUIResponse(response)
.Create();
createRoom(config);
}
});
Update 21/3/2016:
Friends finally appear on the dialog's UI after 3 days of development. Why there is a delay like this?

Answer 1

Try to check your RealTimeMultiplayerManager::ShowPlayerSelectUI method if you misconfigured something. Here is a sample snippet.
void Engine::InviteFriend() {
service_->RealTimeMultiplayer().ShowPlayerSelectUI(
MIN_PLAYERS, MAX_PLAYERS, true,
[this](gpg::RealTimeMultiplayerManager::PlayerSelectUIResponse const &
response) {
LOGI("inviting friends %d", response.status);
// Your code to handle the users's selection goes here.
});
}
You can also look into this Adding Real-time Multiplayer Support to Your Game documentation to check your configuration.