Measuring time Interval Since Now

myles picture myles · May 26, 2011 · Viewed 22.4k times · Source

anyone know or can provide some example code relating to "timeIntervalSinceNow" method...

I need something like... time2(when app eneters foreground) - time1(when app enters background) = time3(the difference in times)... this is so i can use this number(pref in seconds) to calculate the time i have lost while the app has been in background !!

I am having trying trying to create the date objects, receive the object and display/use in a label....

Answer

bob s picture bob s · Jul 29, 2012

Actually, to answer your original question, myles, you can use timeIntervalSinceNow. In the statement below, inputDate has been initialized as an NSDate and set to some date (you could just try [NSDate *inputDate = [NSDate date]; to set the date at the current date and time.

NSTimeInterval timeToAlert =[inputDate timeIntervalSinceNow];

The next line is a way to put that NSTimeInterval into a string.

NSMutableString *timeinterval = [NSMutableString string];
[timeinterval appendFormat:@"%f",timeToAlert];

Finally, the app delegate class is typically where code can be written to handle coming in and out of background. Good luck!