对于OS X上的细粒度计时，您应该使用在<mach/mach_time.h>中声明的mach_absolute_time():

#include <mach/mach_time.h>
#include <stdint.h>

// Do some stuff to setup for timing
const uint64_t startTime = mach_absolute_time();
// Do some stuff that you want to time
const uint64_t endTime = mach_absolute_time();

// Time elapsed in Mach time units.
const uint64_t elapsedMTU = endTime - startTime;

// Get information for converting from MTU to nanoseconds
mach_timebase_info_data_t info;
if (mach_timebase_info(&info))
   handleErrorConditionIfYoureBeingCareful();

// Get elapsed time in nanoseconds:
const double elapsedNS = (double)elapsedMTU * (double)info.numer / (double)info.denom;

当然，关于细粒度度量的通常警告也适用;您可能最好多次调用测试中的例程，并求平均值/取最小值/一些其他形式的处理。

此外，请注意，您可能会发现使用Shark等工具对应用程序运行进行概要分析更有用。这不会为您提供确切的时间信息，但它会告诉您应用程序的时间在哪里花费了多少百分比，这通常更有用(但并不总是如此)。

我使用非常少的，一页的类实现，灵感来自这篇博客文章的代码:

#import <mach/mach_time.h>

@interface DBGStopwatch : NSObject

+ (void)start:(NSString *)name;
+ (void)stop:(NSString *)name;

@end

@implementation DBGStopwatch

+ (NSMutableDictionary *)watches {
    static NSMutableDictionary *Watches = nil;
    static dispatch_once_t OnceToken;
    dispatch_once(&OnceToken, ^{
        Watches = @{}.mutableCopy;
    });
    return Watches;
}

+ (double)secondsFromMachTime:(uint64_t)time {
    mach_timebase_info_data_t timebase;
    mach_timebase_info(&timebase);
    return (double)time * (double)timebase.numer /
        (double)timebase.denom / 1e9;
}

+ (void)start:(NSString *)name {
    uint64_t begin = mach_absolute_time();
    self.watches[name] = @(begin);
}

+ (void)stop:(NSString *)name {
    uint64_t end = mach_absolute_time();
    uint64_t begin = [self.watches[name] unsignedLongLongValue];
    DDLogInfo(@"Time taken for %@ %g s",
              name, [self secondsFromMachTime:(end - begin)]);
    [self.watches removeObjectForKey:name];
}

@end

它的用法很简单:

调用[DBGStopwatch start:@"slow-operation"];一开始 然后[DBGStopwatch stop:@"slow-operation"];做完之后，才能得到时间

我使用基于Ron的解决方案的宏。

#define TICK(XXX) NSDate *XXX = [NSDate date]
#define TOCK(XXX) NSLog(@"%s: %f", #XXX, -[XXX timeIntervalSinceNow])

对于代码行:

TICK(TIME1);
/// do job here
TOCK(TIME1);

我们将在控制台中看到如下内容:TIME1: 0.096618

对于Swift 4，添加一个委托到你的类:

public protocol TimingDelegate: class {
    var _TICK: Date?{ get set }
}

extension TimingDelegate {
    var TICK: Date {
        _TICK = Date()
        return(_TICK)!
     }

    func TOCK(message: String)  {

        if (_TICK == nil){
            print("Call 'TICK' first!")
        }

        if (message == ""){
            print("\(Date().timeIntervalSince(_TICK!))")
        }
        else{
            print("\(message): \(Date().timeIntervalSince(_TICK!))")
        }
    }
}

加入我们班:

class MyViewcontroller: UIViewController, TimingDelegate

然后添加到你的类:

var _TICK: Date?

当你想为某事计时时，可以从以下开始:

TICK

最后:

TOCK("Timing the XXX routine")

你可以得到很好的时间(秒。部分秒)使用这个StopWatch类。它使用了iPhone的高精度计时器。使用NSDate只能获得秒级精度。这个版本是专门为自动发布和objective-c设计的。如果需要的话，我也有一个c++版本。你可以在这里找到c++版本。

StopWatch.h

#import <Foundation/Foundation.h>


@interface StopWatch : NSObject 
{
    uint64_t _start;
    uint64_t _stop;
    uint64_t _elapsed;
}

-(void) Start;
-(void) Stop;
-(void) StopWithContext:(NSString*) context;
-(double) seconds;
-(NSString*) description;
+(StopWatch*) stopWatch;
-(StopWatch*) init;
@end

StopWatch.m

#import "StopWatch.h"
#include <mach/mach_time.h>

@implementation StopWatch

-(void) Start
{
    _stop = 0;
    _elapsed = 0;
    _start = mach_absolute_time();
}
-(void) Stop
{
    _stop = mach_absolute_time();   
    if(_stop > _start)
    {
        _elapsed = _stop - _start;
    }
    else 
    {
        _elapsed = 0;
    }
    _start = mach_absolute_time();
}

-(void) StopWithContext:(NSString*) context
{
    _stop = mach_absolute_time();   
    if(_stop > _start)
    {
        _elapsed = _stop - _start;
    }
    else 
    {
        _elapsed = 0;
    }
    NSLog([NSString stringWithFormat:@"[%@] Stopped at %f",context,[self seconds]]);

    _start = mach_absolute_time();
}


-(double) seconds
{
    if(_elapsed > 0)
    {
        uint64_t elapsedTimeNano = 0;

        mach_timebase_info_data_t timeBaseInfo;
        mach_timebase_info(&timeBaseInfo);
        elapsedTimeNano = _elapsed * timeBaseInfo.numer / timeBaseInfo.denom;
        double elapsedSeconds = elapsedTimeNano * 1.0E-9;
        return elapsedSeconds;
    }
    return 0.0;
}
-(NSString*) description
{
    return [NSString stringWithFormat:@"%f secs.",[self seconds]];
}
+(StopWatch*) stopWatch
{
    StopWatch* obj = [[[StopWatch alloc] init] autorelease];
    return obj;
}
-(StopWatch*) init
{
    [super   init];
    return self;
}

@end

该类有一个返回自动释放对象的静态stopWatch方法。

调用start后，使用seconds方法获取运行时间。再次调用start来重新启动它。或者停下来停下来。在调用stop后，您仍然可以随时读取时间(调用秒数)。

函数中的示例(执行的定时调用)

-(void)SomeFunc
{
   StopWatch* stopWatch = [StopWatch stopWatch];
   [stopWatch Start];

   ... do stuff

   [stopWatch StopWithContext:[NSString stringWithFormat:@"Created %d Records",[records count]]];
}

许多答案很奇怪，并没有真正以毫秒为单位给出结果(而是以秒或其他单位):

这里是我用来获得MS(毫秒):

迅速:

let startTime = NSDate().timeIntervalSince1970 * 1000

// your Swift code

let endTimeMinusStartTime = NSDate().timeIntervalSince1970 * 1000 - startTime
print("time code execution \(endTimeMinStartTime) ms")

objective - c:

double startTime = [[NSDate date] timeIntervalSince1970] * 1000.0;

// your Objective-C code

double endTimeMinusStartTime = [[NSDate date] timeIntervalSince1970] * 1000.0 - startTime;
printf("time code execution %f ms\n", endTimeMinusStartTime );