iPhone：日期轉換問題

Question

我需要檢查一個事件日期，該日期應該在當前日期和從現在起的60天之間。下面的代碼被使用，但它不能正常工作。請注意，我收到來自服務器的事件字符串 - 「2012-04-14T16：50：02Z」。

// current date 
double currDateInMilliSecs = [NSDate timeIntervalSinceReferenceDate] * 1000;  
NSLog(@"currDateInMilliSecs: %f", currDateInMilliSecs); 

// sixty days 
double sixtydaysvalue = 60.0 * 24.0 * 3600.0 * 1000.0; 
NSLog(@"sixtydaysvalue: %f", sixtydaysvalue); 
// add current date + sixt days 
double sixtyDaysMilliSecsFromCurrDate = currDateInMilliSecs + sixtydaysvalue; 
NSLog(@"sixtyDaysMilliSecsFromCurrDate: %f", sixtyDaysMilliSecsFromCurrDate); 

// check does the event date between current date + 60 days 
NSDateFormatter *df = [[NSDateFormatter alloc] init]; 
//[df setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]]; 
[df setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"]; 
//[df setDateFormat:@"yyyy-MM-dd HH:mm:ss"]; 

// [eventDict objectForKey:@"begin_at"] gives date string like this "2012-04-14T16:50:02Z" for ex. 
NSDate *eventdate = [df dateFromString:[eventDict objectForKey:@"begin_at"]]; 

NSTimeInterval nowSinceEventDate = [eventdate timeIntervalSince1970]; 
NSLog(@"nowSinceEventDate: %f", nowSinceEventDate); 
double eventDateInMilliSecs = nowSinceEventDate * 1000; 
NSLog(@"eventDateInMilliSecs: %f", eventDateInMilliSecs); 

// this is not working as expected  
if (eventDateInMilliSecs<sixtyDaysMilliSecsFromCurrDate && eventDateInMilliSecs>currDateInMilliSecs) 
{ 


} 
else 
{ 
} 

請幫忙嗎？

Answer 1

NSDateFormatter *df = [[NSDateFormatter alloc] init]; 
[df setDateFormat:@"yyyy-MM-dd HH:mm:ss:SSS"]; 
// [eventDict objectForKey:@"begin_at"] gives "2012-04-14T16:50:02Z" 
NSDate *eventdate = [df dateFromString:[eventDict objectForKey:@"begin_at"]]; 

[DF setDateFormat：@ 「YYYY-MM-DD HH：MM：SS」];

SSS的毫秒數

Answer 2

試試這個：

NSString *dateString = @"2012-04-14T16:50:02Z"; 

NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; 
[formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"]; 
NSDate *eventDate = [formatter dateFromString:dateString]; 

NSTimeInterval nowSinceEventDate = [eventDate timeIntervalSince1970]; 
NSLog(@"interval = %f", nowSinceEventDate); 

UPDATE：

NSString *dateString = @"2012-05-21T16:50:02Z"; 

NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; 
[formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"]; 
NSDate *eventDate = [formatter dateFromString:dateString]; 

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; 
NSDateComponents *components = [[NSDateComponents alloc] init]; 
[components setDay:60]; 

NSDate *minDate = [NSDate date]; 
NSDate *maxDate = [gregorian dateByAddingComponents:components toDate:minDate options:0]; 

NSLog(@"eventDate interval = %f", [eventDate timeIntervalSince1970]); 
NSLog(@"minDate interval = %f", [minDate timeIntervalSince1970]); 
NSLog(@"maxDate interval = %f", [maxDate timeIntervalSince1970]); 

BOOL isBetween = (([eventDate compare:minDate] == NSOrderedDescending) && ([eventDate compare:maxDate] == NSOrderedAscending)); 
NSLog(@"isBetween = %d", isBetween); 

Answer 3

試試這個

[dateFormatter setDateFormat：@「yyyy-MM-dd'T'HH：mm：ss SSS」];