错位NSTimer

Question

我有3种不同的NSTimers，我想每0.3秒钟触发一次，但我希望3 NSTimers被交错，这样它们就不会同时开火。例如，NSTimer1火灾在0.1，然后在0.4，NSTimer2火灾在0.2，然后在0.5，NSTimer3火灾在0.3，然后在0.6，等等。

下面是我目前正在使用的东西，我不确定它们是否真的同时发射，我只是假设。如有任何建议，将不胜感激。

var timer1 = NSTimer.scheduledTimerWithTimeInterval(0.3, target: self, selector: Selector("updateSegment1"), userInfo: nil, repeats: true)
var timer2 = NSTimer.scheduledTimerWithTimeInterval(0.3, target: self, selector: Selector("updateSegment2"), userInfo: nil, repeats: true)
var timer3 = NSTimer.scheduledTimerWithTimeInterval(0.3, target: self, selector: Selector("updateSegment3"), userInfo: nil, repeats: true)

Answer 1

您可以使用块来完成这一任务。

-(void)didMoveToView:(SKView *)view {

    SKAction *wait0 = [SKAction waitForDuration:0.1];
    SKAction *block0 = [SKAction runBlock:^{
        // run first timer code
    }];
    [self runAction:[SKAction sequence:@[wait0, block0]]];

    SKAction *wait1 = [SKAction waitForDuration:0.2];
    SKAction *block1 = [SKAction runBlock:^{
        // run second timer code
    }];
    [self runAction:[SKAction sequence:@[wait1, block1]]];

    SKAction *wait2 = [SKAction waitForDuration:0.3];
    SKAction *block2 = [SKAction runBlock:^{
        // run third timer code
    }];
    [self runAction:[SKAction sequence:@[wait2, block2]]];

}

如果你想使用调度，试试下面的代码.

为计时器创建一个属性：

@property (nonatomic, strong) dispatch_source_t myTimer;

接下来，创建定时器：

// Get the queue to run the blocks on
dispatch_queue_t queue = dispatch_get_main_queue();

// Create a dispatch source, and make it into a timer that goes off every second
self.myTimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
dispatch_source_set_timer(self.myTimer, DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC, 0);

// When the timer goes off, run your code
dispatch_source_set_event_handler(self.myTimer, ^{
    //code...
});

// Dispatch sources start out paused, so start the timer by resuming it
dispatch_resume(self.myTimer);

// To cancel the timer, just set the timer variable to nil:
self.myTimer = nil;

Answer 2

我建议您在雪碧套件游戏中使用一两个SKAction而不是NSTimer，因为当您暂停/恢复SKView和/或SKScene时，动作会暂停/恢复。下面是一个如何使用SKActions错开事件的示例：

override func didMoveToView(view:SKView) {

    let wait = SKAction.waitForDuration(0.1)
    let block1 = SKAction.runBlock({
        updateSegment1()
    })
    let block2 = SKAction.runBlock({
        updateSegment2()
    })
    let block3 = SKAction.runBlock({
        updateSegment3()
    })
    let sequence = SKAction.sequence([wait,block1,wait,block2,wait,block3])
    self.runAction(SKAction.repeatActionForever(sequence), withKey:"timer")

    // Use the following to terminate the timer
    //self.removeActionForKey("timer")
}