Generate random time for subactions inside of repe

问题:

Hi I'm trying to generate random time intervals everytime the action is repeated but it only generates the time interval randomly only when the vied did load.

Here is my code :

 let moveBucketLeft = SKAction.moveByX(400, y: 0, duration: NSTimeInterval(grabRandomTime()))
    let moveBucketRight = SKAction.moveByX(-400, y: 0, duration: NSTimeInterval(grabRandomTime()))
    moveBucketLeftAndRight = SKAction.sequence([moveBucketLeft,moveBucketRight])
    let repeatMovement = SKAction.repeatActionForever(moveBucketLeftAndRight)
    bucket.runAction(repeatMovement)

The method grabRandomTime just generates a random duration between 1 and 5 .

I need all the help I can help. Thank you!

Here's my generate random value method:

func grabRandomTime() ->UInt32{
    var time = arc4random_uniform(6) + 1
    return time
}

And the action runs one time in viewdidload. I think that maybe why it only take a random value one time. I'm not sure how to run the method everytime. I can't process that in my head :/

回答1:

use let wait = SKAction.waitForDuration(sec, **withRange**: dur) instead of duration: NSTimeInterval(grabRandomTime() in your code. SKAction.waitForDuration with withRange parameter will compute random time interval with average=sec and possible range = dur