How to display label text with timestamp as "seconds:milliseconds" in iPhone SDK?

How can I have a timestamp as "ss:mm" where mm = milliseconds?

Please let me kn开发者_运维百科ow.

Getting milliseconds is actually pretty easy. I created a category a while back to do this for me - all you need is a NSTimeInterval.

- (NSNumber *)getMilliseconds 
{
    return [NSNumber numberWithLongLong:[[NSDate date] timeIntervalSince1970] * 1000];
}

So if you want a timestamp with seconds and milliseconds, do this:

 NSDate *today = [NSDate dateWithTimeIntervalSinceNow:0];
 NSDateFormatter *dateFormat = [[[NSDateFormatter alloc] init] autorelease];
 [dateFormat setDateFormat:@"ss"];
 NSString *dateString = [dateFormat stringFromDate:today];

 NSString*mystamp = [NSString stringWithFormat:@"%@:%i",dateString,[self getMilliseconds]];

 NSLog(@"Timestamp with Milliseconds: %@", mystamp);

If course you will have to edit my category if you want a custom date to calculate milliseconds from.

Hope it helps!