How to store time in sharedpreferences across two activities

Question

When my users play a game, I want to lock them out of it for 30 seconds. I'm trying to use SharedPreferences . I'm not well acquainted with SP and not completely sure how to use it. So it should look like so

ifGameOver(){

//lock the game for 30 seconds 
//send users to main menu until 30seconds is over

}

and then at the main menu I wish to be able to see a TextView count down as the 30 seconds go down. So here I would getLong or something(?). Could anyone shed any light on this?

Answer 1

Save current time to SharedPreferences in first Activity class:

private void saveCurrentTIme() {
        SharedPreferences sharedpreferences = getSharedPreferences("myAppPref",
            Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedpreferences.edit();
        editor.putLong("GameTime", System.currentTimeMillis());
        editor.commit();
}

Retrieve saved time from SharedPreferences in second Activity class:

    private long getSavedTime() {
            SharedPreferences sharedpreferences = getSharedPreferences("myAppPref", Context.MODE_PRIVATE);
            return sharedpreferences.getLong(Name, 0L);

     }

For comparing if the saved time is passed, you can create something like Timer .

You can check this answer for how to do it.