点击之间的iOS计时

我试着在敲击声之间保持节奏。然而，我随机得到了巨大的价值，我不知道为什么

@implementation GameScene
{
   CFTimeInterval previousFrameTime;
   SKLabelNode* myLabel;
}

-(void)didMoveToView:(SKView *)view {
   previousTimeFrame = 0.0f;
   myLabel = [SKLabelNode labelNodeWithFontNamed:@"Chalkduster"];

   myLabel.text = @" ";
   myLabel.fontSize = 12;
   myLabel.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame));
[self addChild:myLabel];
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    myLabel.text = [NSSTring stringWithFormat: @"%f", previousFrameTime];
}

//Called every frame
-(void)update:(CFTimeInterval)currentTime {
    //get the time between frames
    previousFrameTime = CACurrentMediaTime() - previousFrameTime;
}

输出： 0.65323 0.93527 1.65326

---

5866.42930我觉得这条线好像断了：

previousFrameTime=CACurrentMediaTime（）-previousFrameTime

让我们看看如果你每秒钟点击一次，这将如何工作，准确地说：

1.) previousFrameTime = 1000 - 0; (1000)
2.) previousFrameTime = 1001 - 1000; (1)
3.) previousFrameTime = 1002 - 1; (1001)
4.) previousFrameTime = 1003 - 1001; (2)

时间增量计算是正确的，但您必须记录最后测量的时间，而不是最后计算的间隔，因此

CFTimeInterval currentMediaTime = CACurrentMediaTime();
CFTimeInterval currentInterval  = currentMediaTime - previousFrameTime;

// use currentInterval however you were using previousFrameTime, but now the
// previous time should be recorded as the current time

previousFrameTime = currentMediaTime;

下面是一个演示如何计算平均点击率的答案-它可能会给您一些帮助