处理时间相差8个小时的方法

[NSDate date]获取的是GMT时间，这个时间和北京时间相差8个小时，以下代码可以解决这个问题

//方法一
- (void)tDate
{
    NSDate *date = [NSDatedate];
    NSTimeZone *zone = [NSTimeZonesystemTimeZone];
    NSInteger interval = [zone secondsFromGMTForDate: date];
    NSDate *localeDate = [date  dateByAddingTimeInterval: interval];  
    NSLog(@"%@", localeDate);
}
方法二
- (NSString*)dateAsString:(NSDate*)date
 {
NSString *returnValue = @"";
    NSDateFormatter *dateFormatter = nil;
if (date != nil) {
if (dateFormatter ==nil) {
dateFormatter = [[NSDateFormatteralloc]init];
}
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterNoStyle];
[dateFormatter setLocale:[NSLocalecurrentLocale]];
returnValue = [dateFormatter stringFromDate:date];
}
return returnValue;
}

//方法三
+ (NSString *)fixStringForDate:(NSDate *)date 
{
    NSDateFormatter* dateFormatter = [[NSDateFormatteralloc]init];
    [dateFormatter setDateStyle:kCFDateFormatterFullStyle];
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString *fixString = [dateFormatter stringFromDate:date]; 
    [dateFormatter release];
    return fixString;
}

//方法四

    NSDateComponents *comps = [[NSDateComponentsalloc]init];
    [comps setYear:2010];
    [comps setMonth:8];
    [comps setDay:24];
    [comps setHour:17];
    [comps setMinute:5];
    [comps setTimeZone: [NSTimeZonetimeZoneWithAbbreviation:@"UTC"]];
    NSLog(@"%@", [NSTimeZonetimeZoneWithAbbreviation:@"UTC"]);
    
    NSCalendar *cal = [[NSCalendaralloc]initWithCalendarIdentifier:NSGregorianCalendar];
    NSDate *referenceTime = [cal dateFromComponents:comps];
    NSLog(@"%@", referenceTime);