//處理伺服器時間的介面 
+(NSString *)currentTime:(NSString *)str timeFormat:(NSString *)timeFormat;

+(NSString *)currentTime:(NSString *)string timeFormat:(NSString *)timeFormat
{
    //把字串轉為NSdate
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:timeFormat];
    NSDate
 
 *timeDate = [dateFormatter dateFromString:string];

    //得到與當前時間差
    NSTimeInterval  timeInterval = [timeDate timeIntervalSinceNow];
    timeInterval = -timeInterval;
    //標準時間和北京時間差8個小時
    timeInterval = timeInterval - 8*60*60;
    long temp = 0;
    NSString *result;
    if (timeInterval < 60) {
        result = [NSString
 
 stringWithFormat:@"剛剛"];
    }
    else if((temp = timeInterval/60) <60){
        result = [NSString stringWithFormat:@"%ld分鐘前",temp];
    }

    else if((temp = temp/60) <24){
        result = [NSString stringWithFormat:@"%ld小時前",temp];
    }

    else if((temp = temp/24) <30){
        result = [NSString
 
 stringWithFormat:@"%ld天前",temp];
    }

    else if((temp = temp/30) <12){
        result = [NSString stringWithFormat:@"%ld月前",temp];
    }
    else{
        temp = temp/12;
        result = [NSString stringWithFormat:@"%ld年前",temp];
    }

    return  result;
}