IOS/Objective-c: dateWithTimeInterval 问题

Question

我不知道这是错字还是什么，但出于某种原因，以下内容不起作用。

我想向 NSDate 添加一秒钟。这样做之前，我检查日期是否为 null 或 nil，如果是，则将其设置为当前日期以避免错误。尽管如此，在尝试添加或减去第二个之后，日期显示为空。谁能指出哪里出了问题？

int secondsAdjustment = 1;
NSDate* myLastViewed = item.lastviewed;
    NSDate* myLastTouched = item.lasttouched;


 if ([myLastViewed isKindOfClass:[NSNull class] ]||myLastViewed==nil) {
        NSLog(@"last viewed null");
        if ([myLastTouched isKindOfClass:[NSNull class]]||myLastTouched==nil) {
            NSLog(@"last touched is also null so set both to now");
             myLastViewed = [NSDate date];
            myLastTouched = [NSDate date];
            NSLog(@"my LastViewed after setting to now is:%@",myLastViewed);
            NSLog(@"my LastTouched after setting to now is:%@",myLastTouched);
        }
        else {
            NSLog(@"last touched is not null so I will set viewed to it");
            myLastViewed=myLastTouched;
        }
    }

if (myLastViewed!=nil&&![myLastViewed isKindOfClass:[NSNull class]]) {
         _lastViewedAdjusted = [NSDate dateWithTimeInterval:secondsAdjustment sinceDate:myLastViewed]; 
NSLog(@"making adjustment"); //THIS Logs  
    }
else {
 NSLog(@"something went wrong"); //THIS DOES NOT.  Never get here
}
NSLog(@"lastViewedAdjusted%@",_lastViewedAdjusted);//THIS IS logging as NULL

Answer 1

你可以只用这个

  NSDate *lastViewedAdjusted = [myLastViewed dateByAddingTimeInterval:1];

IOS/Objective-c: dateWithTimeInterval 问题

IOS/Objective-c: dateWithTimeInterval Issue

objective-c

nsdate

ios