iOS获取当前时间 NSDate（NSCalendar）获取当前时间

新人一枚，如果大家有更好的方法，请大家多多指教。。。

通过NSDate获取当前时间，并格式化输出，以及将已有的字符串（如：@”2015-02-12 13:23:20”）转换为NSDate

/*

获取争取的当地时间

*/

NSDate *senddate=[NSDate date];

NSTimeZone *zone = [NSTimeZone systemTimeZone];

NSInteger interval = [zone secondsFromGMTForDate: senddate];

NSDate *localDate = [senddate dateByAddingTimeInterval: interval];

/*
将时间格式化转成字符串输出
*/
NSDateFormatter  *dateformatter=[[NSDateFormatter alloc] init];
[dateformatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"];
NSString *locationString=[dateformatter stringFromDate:localDate];
NSLog(@"locationString:%@",locationString);

/*
将已有的字符串转换成date
*/
NSString *timeStr = @"2015-02-12 13:23:20";
NSDateFormatter *format=[[NSDateFormatter alloc] init];
[format setDateFormat:@"YYYY-MM-dd HH:mm:ss"];
NSDate *fromdate=[format dateFromString:timeStr];
NSTimeZone *fromzone = [NSTimeZone systemTimeZone];
NSInteger frominterval = [fromzone secondsFromGMTForDate: fromdate];
NSDate *fromDate = [fromdate  dateByAddingTimeInterval: frominterval];
NSLog(@"\nfromDate:%@ \nsenddate:%@",fromDate,localDate);

/*
比较时间
*/
NSComparisonResult result = [localDate compare:fromDate];
if (result == NSOrderedDescending) {
NSLog(@"localDate 比 fromDate 晚");//date1 比 date2 晚
} else if (result == NSOrderedAscending){
NSLog(@"localDate 比 fromDate 早");//date1 比 date2 早
}

方法二

NSArray *weekArray = [[NSArray alloc]initWithObjects:@”星期日”,@”星期一”,@”星期二”,@”星期三”,@”星期四”,@”星期五”,@”星期六”, nil];

NSDate *date = [NSDate date];

NSCalendar *calendar = [NSCalendar currentCalendar];

NSDateComponents *comps;

comps = [calendar components:NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond | NSCalendarUnitWeekday fromDate:date];

NSString *year = [NSString stringWithFormat:@”%zd”,[comps year]-2000];

NSString *month = [NSString stringWithFormat:@”%zd”,[comps month]];

NSString *day = [NSString stringWithFormat:@”%zd”,[comps day]];

NSString *hour = [NSString stringWithFormat:@”%zd”,[comps hour]];

NSString *minute = [NSString stringWithFormat:@”%zd”,[comps minute]];

NSString *second = [NSString stringWithFormat:@”%zd”,[comps second]];

NSString *weekday = nil;

if ([comps weekday] == 1) {

weekday = [NSString stringWithFormat:@”%zd”,[comps weekday]+6];

}else{

weekday = [NSString stringWithFormat:@”%zd”,[comps weekday]-1];

}

NSArray *array = [[NSArray alloc]initWithObjects:year,month,day,hour,minute,second,weekday, nil];