+ (NSString *)getUnixTimeString:(NSString *)timeStr{
    double unixTimeStamp = [timeStr doubleValue];
    NSTimeInterval _interval=unixTimeStamp;
    NSDate *date = [NSDate dateWithTimeIntervalSince1970:_interval];
    NSDateFormatter *_formatter=[[NSDateFormatter alloc]init];
    [_formatter setLocale:[NSLocale currentLocale]];
    [_formatter setDateFormat:@"yyyy.MM.dd kk.mm"];
    NSString * _date=[_formatter stringFromDate:date];
    return _date;
}

+ (NSString *)getUnixTimeInt:(NSInteger)timeInt {

    NSTimeInterval _interval= (double)timeInt;
    NSDate *date = [NSDate dateWithTimeIntervalSince1970:_interval];
    NSDateFormatter *_formatter=[[NSDateFormatter alloc]init];
    [_formatter setLocale:[NSLocale currentLocale]];
    [_formatter setDateFormat:@"yyyy.MM.dd kk.mm"];
    NSString * _date=[_formatter stringFromDate:date];
    return _date;
}

//返回上下午 返回12小时制时间

+(NSDictionary *) changeSptoTwelveTime:(NSString *)spString
{
    NSDate * timeDate = [self changeSpToTime:spString];
    NSString * str1 = [self nsdateToString:timeDate];
    NSString * str2 = [str1 substringWithRange:NSMakeRange(11,5)];
    NSInteger str3 = [[str2 substringWithRange:NSMakeRange(0,2)] integerValue];
    
    NSString * state = nil;
    NSString * time = nil;
    
    if (str3 >= 12) {
        state = @"PM";
    } else{
        state = @"AM";
    }
    
    NSString * str4 = [self nsdateToStrings:timeDate];
    NSString * str5 = [str4 substringWithRange:NSMakeRange(11,5)];
    time = str5;
    NSDictionary * dic = [NSDictionary dictionaryWithObjectsAndKeys:state,@"state",time,@"time",nil];
    
    return dic;
}

///这个方法针对固定格式的时间需求 例如只需要HH:mm 那么传入时间戳以及你所需要的那部分在字符串中所占的位置
+(NSString *)changeSpToTime:(NSString*)spString Start:(NSInteger) start Length:(NSInteger)length//将时间戳转换成NSString并截取相应长度
{
    NSDate * timeDate = [self changeSpToTime:spString];
    NSString * str1 = [self nsdateToString:timeDate];
    NSString * str2 = [str1 substringWithRange:NSMakeRange(start, length)];
    
    return str2;
}

//获取当前系统的时间戳
+(long)getTimeSp{
    
    long time;
    NSDate *fromdate=[NSDate date];
    time=(long)[fromdate timeIntervalSince1970];
    
    return time;
}

//将时间戳转换成NSDate
+(NSDate *)changeSpToTime:(NSString*)spString{
    
    NSDate *confromTimesp = [NSDate dateWithTimeIntervalSince1970:[spString intValue]];
    
    return confromTimesp;
    
}

//将时间戳转换成NSDate,加上时区偏移
+(NSDate*)zoneChange:(NSString*)spString{
    
    NSDate *confromTimesp = [NSDate dateWithTimeIntervalSince1970:[spString intValue]];
    NSTimeZone *zone = [NSTimeZone systemTimeZone];
    NSInteger interval = [zone secondsFromGMTForDate:confromTimesp];
    NSDate *localeDate = [confromTimesp  dateByAddingTimeInterval: interval];
    
    return localeDate;
}

//比较给定NSDate与当前时间的时间差，返回相差的秒数
+(long)timeDifference:(NSDate *)date{
    
    NSDate *localeDate = [NSDate date];
    long difference =fabs([localeDate timeIntervalSinceDate:date]);
    
    return difference;
}

//将NSDate按yyyy-MM-dd HH:mm:ss格式时间输出
+(NSString*)nsdateToString:(NSDate *)date{
    
    NSDateFormatter *dateFormat=[[NSDateFormatter alloc]init];
    [dateFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString* string=[dateFormat stringFromDate:date];
    
    return string;
}

//将NSDate按yyyy-MM-dd hh:mm:ss格式时间输出
+(NSString*)nsdateToStrings:(NSDate *)date{
    
    NSDateFormatter *dateFormat=[[NSDateFormatter alloc]init];
    [dateFormat setDateFormat:@"yyyy-MM-dd hh:mm:ss"];
    NSString* string=[dateFormat stringFromDate:date];
    
    return string;
}

//将yyyy-MM-dd HH:mm:ss格式时间转换成时间戳
+(long)changeTimeToTimeSp:(NSString *)timeStr{
    
    long time;
    NSDateFormatter *format=[[NSDateFormatter alloc] init];
    [format setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSDate *fromdate=[format dateFromString:timeStr];
    time= (long)[fromdate timeIntervalSince1970];
    
    return time;
}

//获取当前系统的yyyy-MM-dd HH:mm:ss格式时间
+(NSString *)getTime{
    
    NSDate *fromdate=[NSDate date];
    NSDateFormatter *dateFormat=[[NSDateFormatter alloc]init];
    [dateFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString* string=[dateFormat stringFromDate:fromdate];
    
    return string;
}