countdown in swift and spritekit

问题:

I'm trying to put a countDown on my application. I'm using a SKLabelNode. This is my code :

class PlayScene: SKScene {
    var startCount = true
    var setTime = 0
    var myTime = 0
    var printTime = SKLabelNode(fontNamed: "arial")
    override func didMoveToView(view: SKView!) {
        self.backgroundColor = UIColor(hex: 0xD64541)
        self.printTime.text = NSString(format: "%i", self.myTime)
        self.addChild(self.printTime)
    }
    override func update(currentTime: NSTimeInterval) {
        if self.startCount == true {
            self.setTime = Int(currentTime)
            self.startCount = false
        }
        self.myTime = Int(currentTime) - self.setTime
        }
  }

I had no problem to compile it but it's crashing at the execution... I think that's coming from my convertion in string..

Thank you

回答1:

float  timeforFunction;
   int numberoftime;
   int __totalscore;
   timeforFunction=1.5f;
   numberoftime=10;

    SKAction *updateTime= [SKAction sequence:@[
                                               [SKAction waitForDuration: timeforFunction],
                                               [SKAction performSelector:@selector(updatescore)
                                                                onTarget:self]

                                               ]];
    [self runAction:[SKAction repeatAction:updateTime count: numberoftime] withKey:@"zorbTime"];


   -(void) updatescore
{
    __totalscore+=1;
   _GamescoreText.text = [NSString stringWithFormat:@“%i”, __totalscore];
}

if you wanna repeat this action forever just change to

[self runAction:[SKAction repeatAction:updateTime count: numberoftime] withKey:@"zorbTime"];

回答2:

I hope this helps. you almost had it

class PlayScene: SKScene {

var startCount = true
var setTime = 0
var myTime = 0
var printTime = SKLabelNode(fontNamed: "arial")

override func didMoveToView(view: SKView) {
    self.backgroundColor = UIColor.orangeColor()

    //self.printTime.text = NSString(format: "%i", self.myTime)//you need the position
    self.printTime.position = CGPointMake(self.size.width * 0.5, self.size.height * 0.5)
    self.addChild(self.printTime)
}
override func update(currentTime: NSTimeInterval) {
    if self.startCount == true {
        self.setTime = Int(currentTime)
        self.startCount = false
    }
    self.myTime = Int(currentTime) - self.setTime
     self.printTime.text = ("format:\(self.myTime)")//put your label in update so it shows each second.
}

回答3:

Here's how I solved this problem for my Swift/SpriteKit 'Breakout' application. I wanted a countdown from 5 to 1 onthe main game screen but before the ball started to move. I Added these functions and then a call to countdown(5) at the end of didMoveToView: Notice the ball.physicsBody!.applyImpulse(CGVectorMake(20, 20)) as the last step of endCountdownwhich starts the ball and effectively starts the game.

func countdown(count: Int) {
    countdownLabel.horizontalAlignmentMode = .Center
    countdownLabel.verticalAlignmentMode = .Baseline
    countdownLabel.position = CGPoint(x: size.width/2, y: size.height*(1/3))
    countdownLabel.fontColor = SKColor.whiteColor()
    countdownLabel.fontSize = size.height / 30
    countdownLabel.zPosition = 100
    countdownLabel.text = "Launching ball in \(count)..."

addChild(countdownLabel)

let counterDecrement = SKAction.sequence([SKAction.waitForDuration(1.0),
    SKAction.runBlock(countdownAction)])

runAction(SKAction.sequence([SKAction.repeatAction(counterDecrement, count: 5),
    SKAction.runBlock(endCountdown)]))

}

func countdownAction() {
    count--
    countdownLabel.text = "Launching ball in \(count)..."
}

func endCountdown() {
    countdownLabel.removeFromParent()
    ball.physicsBody!.applyImpulse(CGVectorMake(20, 20))
}