在iOS中启动计时器倒数

Question

I have a task in which I need to start timer countdown and I have days, hours, minutes and seconds but don't have any idea how to start timer with these entities. There are so many tutorials for counter but none of them were as per my requirement. For example, I'll get 20 days, 10 hours, 40 minutes and 30 seconds as ending date and starting date from server and I need to start timer from these entities. Please suggest me how to do that?

Answer 1

You need to go with NSDateComponents

NSDate* result;
    NSDateComponents *comps = [[NSDateComponents alloc] init];
    [comps setMinute:0];/ use your retrieved values
    [comps setHour:0];
    NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    result = [gregorian dateFromComponents:comps];

Use the NSDate into the NSTimer