小賢的部落格

.h檔

#import <mach/mach_time.h>

.m

使用mach_absolute_time()

- (IBAction)authHandler:(UIButton *)sender

{

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        constuint64_t startTime = mach_absolute_time();

        NSString *token = [selfauth];

        constuint64_t endTime = mach_absolute_time();

        constuint64_t elapsedMTU = endTime - startTime;

        double miliseconds = [selfMachTimeToMiliseconds:elapsedMTU];

        NSLog(@"Auth: %f", miliseconds);

        dispatch_async(dispatch_get_main_queue(), ^{

            self.tokenLabel.text = token;

        });

    });

}

/**

 * 將MTU轉成Miliseconds

 */

- (double)MachTimeToMiliseconds:(constuint64_t)elapsedMTU

{

    // Get information for converting from MTU to nanoseconds

    mach_timebase_info_data_t info;

    mach_timebase_info(&info);

    // Get elapsed time in nanoseconds:

    constdouble elapsedNS = (double)elapsedMTU * (double)info.numer / (double)info.denom / 1e6;

    return elapsedNS;

}

2016/05/09 更新:

這兩種也是可以用來測量程式執行時間

let startTime = CFAbsoluteTimeGetCurrent() (iOS 8.0 +)

let startTime = CACurrentMediaTime() (iOS 2.0 +)

參考資料:

1.http://stackoverflow.com/questions/3540234/high-resolution-timer-for-iphone

2.http://stackoverflow.com/questions/2129794/how-to-log-a-methods-execution-time-exactly-in-milliseconds

3.http://blog.csdn.net/lengshengren/article/details/19034401