applicationWillTerminate works as long as I don't switch off the iPhone

Question

to save some variables of my apps I use:

-(void)applicationWillTerminate:(UIApplication *)application {

NSUserDefaults *prefs = [NSUserDefaults standardU         


        

Answer 1

If you mean hitting the lock button on the top of the phone by saying "switching on/off", then it won't work, because locking the phone does not cause an application to quit. Your applicationWillTerminate: method is only called when you exit you're application to the home screen or to some other application. When the user presses the Sleep button, applicationWillResignActive: will be send to your application-delegate.

Apple's iPhone OS Programming Guide has a section on handling interruptions.

Answer 2

According to Apple's documentation

"NSUserDefaults caches the information to avoid having to open the user’s defaults database each time you need a default value."

If you want to make sure things are saved you should call "synchronize" on your prefs.