ios 时间差计算 转

//模拟windows下 GetTickCount //

//#import<mach/mach_time.h>

+ (int)mxGetTickCount;

{

   int timeTick;

   mach_timebase_info_data_t info;

   uint64_t machineTime;

   mach_timebase_info(&info);

    machineTime =mach_absolute_time();

    timeTick = machineTime * info.numer / info.denom /1000000LL;

    

   return timeTick;

}

// NSDate timeIntervalSinceDate:

//下面转换NSString，用在保存时间时使用。

 - (double)GetStringTimeDiff:(NSString*)timeS timeE:(NSString*)timeE

{
    
    double timeDiff = 0.0;
    
    NSDateFormatter *formatters = [[NSDateFormatter alloc] init];
    [formatters setDateFormat:@"yyyy/MM/dd HH:mm:ss:SSS"];
    NSDate *dateS = [formatters dateFromString:timeS];
    
    
    
    NSDateFormatter *formatterE = [[NSDateFormatter alloc] init];
    [formatterE setDateFormat:@"yyyy/MM/dd HH:mm:ss:SSS"];
    NSDate *dateE = [formatterE dateFromString:timeE];
    
    
    timeDiff = [dateE timeIntervalSinceDate:dateS ];
    
    return timeDiff;
    
}

- (NSString*)GetCurTime

{
    
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    
    [formatter setDateFormat:@"yyyy/MM/dd HH:mm:ss:SSS"];
    
    NSString*timeString=[formatter stringFromDate: [NSDate date]];
    
    [formatter release];
    
    return timeString;
}