Best strategy to make the user invite his friends on Android?

So I'm builing an Android social game.

What's the best strategy to get the user invite his friends in the game ? How to mix facebook connect, SMS, emails from the contact list ? What application does this perfectly in the minimum amoun开发者_StackOverflow中文版t of steps.

Try using the ACTION_SEND intent, like this:

    Intent shareIntent = new Intent(android.content.Intent.ACTION_SEND);
    shareIntent.setType("text/plain");
    shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "Try (your game) for Android!");
    shareIntent.putExtra(android.content.Intent.EXTRA_TEXT, "I'm using (your game) for Android and I recommend it. Click here: http://www.yourdomain.com");

    Intent chooserIntent = Intent.createChooser(shareIntent, "Share with");
    chooserIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(chooserIntent);   

This code will present a menu with all the applications that can send messages, including Facebook, Twitter, SMS, email, ...etc. The only limitation is that you can only share links with Facebook, so EXTRA_SUBJECT must be a pure URL or the user will get an error if they choose Facebook. In other words only this will work with Facebook:

    shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "http://www.yourdomain.com");

If you want to share other text (like in the example above) you must create a separate share function for Facebook.

Barry