Run two SKActions at once

问题:

I'm using a sequence to run a list of SKActions. What I want to do however, is run an SKAction, then run two at once, then run one in sequence.

Here is my code:

SKNode *ballNode = [self childNodeWithName:@"ball"];

    if (ballNode != Nil){
        ballNode.name = nil;

        SKAction *delay = [SKAction waitForDuration:3];
        SKAction *scale = [SKAction scaleTo:0 duration:1];
        SKAction *fadeOut = [SKAction fadeOutWithDuration:1];
        SKAction *remove = [SKAction removeFromParent];

        //put actions in sequence
        SKAction *moveSequence = [SKAction sequence:@[delay, (run scale and fadeout at the same time), remove]];

        //run action from node (child of SKLabelNode)
        [ballNode runAction:moveSequence];
    }

How can I accomplish this? I'm assuming I can't use a sequence?

回答1:

Use a group action.

From sprite kit programming guide:

A group action is a collection of actions that all start executing as soon as the group is executed. You use groups when you want actions to be synchronized

SKSpriteNode *wheel = (SKSpriteNode*)[self childNodeWithName:@"wheel"];
CGFloat circumference = wheel.size.height * M_PI;
SKAction *oneRevolution = [SKAction rotateByAngle:-M_PI*2 duration:2.0];
SKAction *moveRight = [SKAction moveByX:circumference y:0 duration:2.0];
SKAction *group = [SKAction group:@[oneRevolution, moveRight]];
[wheel runAction:group];

回答2:

A example in Swift would be:

    let textLabel = SKLabelNode(text: "Some Text")

    let moveTo = CGPointMake(600, 20)

    let big = SKAction.scaleTo(3.0, duration: 0.1)
    let med = SKAction.scaleTo(1.0, duration: 0.3)
    let reduce = SKAction.scaleTo(0.2, duration: 1.0)
    let move = SKAction.moveTo(moveTo, duration: 1.0)
    let fade = SKAction.fadeOutWithDuration(2.0)
    let removeNode = SKAction.removeFromParent()
    let group = SKAction.group([fade, reduce])

    let sequence = SKAction.sequence([big, med, move, group, removeNode])

    self.addChild(textLabel)
    textLabel.runAction(sequence)