比较当前日期和时间iOS

Question

NSDate *currentTime = [NSDate date];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
                         [dateFormatter setDateFormat:@"hh:mm"];
NSString *resultString = [dateFormatter stringFromDate: currentTime];
NSDate* firstDate = [dateFormatter dateFromString:resultString];
NSDate* secondDate = [dateFormatter dateFromString:@"16:00"];
NSTimeInterval timeDifference = [secondDate timeIntervalSinceDate:firstDate];

if (timeDifference < 0){

我正在尝试检索当前时间并将其与输入时间进行比较。 到目前为止，这是我代码的一部分（iOS中的目标c），但是NSTimeInterval会导致断点。 除此之外，我还想将日期纳入比较中，因此，如果在星期二5:00 pm之后会发生一个事件。 因此，如果您对如何将其整合也有任何想法，将不胜感激！

Answer 1

比较两个日期：

if ([firstDate compare:secondDate] == NSOrderedDescending) {
    NSLog(@"firstDate is later than secondDate");
    NSTimeInterval timeDifference = [firstDate timeIntervalSinceDate:secondDate];
} else if ([firstDate compare:secondDate] == NSOrderedAscending) {
    NSLog(@"firstDate is earlier than secondDate");
    NSTimeInterval timeDifference = [secondDate timeIntervalSinceDate:firstDate];
} else {
    NSLog(@"firstDate and secondDate are the same");
}

这应该可以解决您的问题。

Answer 2

NSDate *currentTime = [NSDate date];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
                         [dateFormatter setDateFormat:@"hh:mm"];
NSString *resultString = [dateFormatter stringFromDate: currentTime];
NSDate* firstDate = [dateFormatter dateFromString:resultString];
NSDate* secondDate = [dateFormatter dateFromString:@"16:00"];
 NSComparisonResult result = [secondDate compare:firstDate];
        switch(result){
            case NSOrderedDescending:
                NSLog(@"date1 is later than date2");
                break;
            case NSOrderedAscending:
                NSLog(@"date1 is earlier than date2");
                break;
            default:
                NSLog(@"dates are the same");
                break;
         }