使用 mach_absolute_time 和下面黄金鹰所解释的简单的 NSDate 方法之间有什么区别吗?
这里有一个使用 mach 方法的优秀解释...
和
使用 mach_absolute_time 和下面黄金鹰所解释的简单的 NSDate 方法之间有什么区别吗?
这里有一个使用 mach 方法的优秀解释...
和
loop
{
NSDate *start = [NSDate date];
// a considerable amount of difficult processing here
// a considerable amount of difficult processing here
// a considerable amount of difficult processing here
NSDate *methodFinish = [NSDate date];
NSTimeInterval executionTime = [methodFinish timeIntervalSinceDate:start];
NSLog(@"Execution Time: %f", executionTime);
}
应该可以工作。
根据之前的答案,我实现了一个简单的类来测量时间
工作原理:
ABTimeCounter *timer = [ABTimeCounter new];
[timer restart];
//do some calculations
[timer pause];
//do some other staff
[timer resume];
//other code
//You can measure current time immediately
NSLog(@"Time left from starting calculations: %f seconds",[timer measuredTime]);
[timer pause];
@interface ABTimeCounter : NSObject
@property (nonatomic, readonly) NSTimeInterval measuredTime;
- (void)restart;
- (void)pause;
- (void)resume;
@end
.m文件:
@interface ABTimeCounter ()
@property (nonatomic, strong) NSDate *lastStartDate;
@property (nonatomic) BOOL isCounting;
@property (nonatomic, readwrite) NSTimeInterval accumulatedTime;
@end
@implementation ABTimeMeasure
#pragma mark properties overload
- (NSTimeInterval) measuredTime
{
return self.accumulatedTime + [self p_timeSinceLastStart];
}
#pragma mark - public -
- (void) restart
{
self.accumulatedTime = 0;
self.lastStartDate = [NSDate date];
self.isCounting = YES;
}
- (void) pause
{
if (self.isCounting){
self.accumulatedTime += [self p_timeSinceLastStart];
self.lastStartDate = nil;
self.isCounting = NO;
}
}
- (void) resume
{
if (!self.isCounting){
self.lastStartDate = [NSDate date];
self.isCounting = YES;
}
}
#pragma mark - private -
- (NSTimeInterval) p_timeSinceLastStart
{
if (self.isCounting){
return [[NSDate date] timeIntervalSinceDate:self.lastStartDate];
}
else return 0;
}
@end