從dateFromString方法返回的日期

Question

請幫我解決問題。

（我得到的firstDate，secondDate錯誤的日期。）（對於該值objValidation.aRange.MinimumValue，objValidation.aRange.MaximumValue來自Web服務）

NSDateFormatter *df = [[NSDateFormatter alloc] init]; 
       [df setDateFormat:@"MM/dd/yyyy"]; 
       [df setTimeZone:[NSTimeZone localTimeZone]]; 
       NSDate *myDate = [df dateFromString:inputString]; 
       [df setDateFormat:@"MM/dd/yyyy"]; 
       NSLog(@"objValidation.aRange.MinimumValue : %@,objValidation.aRange.MaximumValue :%@, inputString : %@",objValidation.aRange.MinimumValue,objValidation.aRange.MaximumValue,inputString); 
       NSDate *firstDate = [df dateFromString:objValidation.aRange.MinimumValue]; 
       NSDate *secondDate = [df dateFromString:objValidation.aRange.MaximumValue]; 
       NSLog(@"myDate : %@,firstDate :%@, secondDate : %@",myDate,firstDate,secondDate); 
       [df release]; 

輸出：

objValidation.aRange.MinimumValue : 8/20/2013 
objValidation.aRange.MaximumValue :12/31/9999 
inputString : 08/22/2013 
myDate : 2013-08-21 18:30:00 +0000 
firstDate :2013-08-19 18:30:00 +0000 
secondDate : 1999-12-30 18:30:00 +0000 

Answer 1

重新調整的日期是正確的，但您不考慮時區。

全部NSDate對象沒有時區。所以當你解析日期時系統時區將被使用。

Answer 2

試試這個代碼：

NSDateFormatter *df = [[NSDateFormatter alloc] init]; 
[df setDateFormat:@"MM/dd/yyyy"]; 
NSDate *date = [df dateFromString:@"8/20/2013"]; 
NSTimeZone *currentTimeZone = [NSTimeZone localTimeZone]; 
NSTimeZone *utcTimeZone = [NSTimeZone timeZoneWithAbbreviation:@"UTC"]; 
NSInteger currentGMTOffset = [currentTimeZone secondsFromGMTForDate:date]; 
NSInteger gmtOffset = [utcTimeZone secondsFromGMTForDate:date]; 
NSTimeInterval gmtInterval = currentGMTOffset - gmtOffset; 
NSDate *destinationDate = [[NSDate alloc] initWithTimeInterval:gmtInterval sinceDate:date]; 
NSLog(@"DateString : %@", destinationDate); 

你會得到你想要精確的輸出。