Question

到目前为止，我已经创建了一个从底部开始并使用UiDynamicAnimator向上移动的矩形。我希望用户确定负重力的“强度”。我希望用户通过滑块确定值。

到目前为止，这是我的代码：

https://graph.facebook.com/v2.3/oauth/access_token?client_id={my-appid}&redirect_uri={response-handler-script-uri}&client_secret={app-secret-code}&code={a-long-code}

我收到两个错误：

“暧昧地使用'价值'”和 “使用未解析的标识符'theliderValue'”

如何将'sliderValue'转换为只有一个小数点的浮点数？

Answer 1

你的代码遗漏了一些东西。 sliderValue是一个未解析的标识符，因为您只在sliderChanged中声明它，但在viewDidLoad的主体中引用它。另外，我认为你对值的使用是模糊的，因为你已经将函数的参数声明为AnyObject，其值可以是许多东西中的任何一个！

您的代码缺少一种机制，将滑块值的变化与重力行为的变化联系起来。因此，我使用附加到滑块对象的显式目标实现了这一点。我还扔了一个标签，显示了重力的大小。这非常粗糙，但我认为它实现了你想要做的事情。

import UIKit

class ViewController: UIViewController {

    var dynamicAnimator : UIDynamicAnimator!
    var gravityBehaviour : UIGravityBehavior!
    var orangeSquare : UIView!
    var slider : UISlider!
    var sliderLabel : UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Subviews
        self.orangeSquare = {
            let oS : UIView = UIView(frame: CGRect(origin: CGPoint(x: (self.view.frame.width / 2) - 100, y: 500), size: CGSize(width: 200, height: 200)))
            oS.backgroundColor = UIColor.orange
            return oS
        }()

        self.slider = UISlider(frame: CGRect(origin: CGPoint(x: 100, y: 100), size: CGSize(width: self.view.frame.width - 400, height: 50)))
        self.slider.addTarget(self, action: #selector(self.sliderValueDidChange), for: UIControlEvents.allTouchEvents)
        self.slider.minimumValue = -5
        self.slider.maximumValue = 5
        self.slider.value = 0

        self.sliderLabel = UILabel(frame: CGRect(origin: CGPoint(x: self.view.frame.width - 100, y: 100), size: CGSize(width : 50, height: 50)))
        self.sliderLabel.backgroundColor = UIColor.red
        self.sliderLabel.textAlignment = NSTextAlignment.center
        self.sliderLabel.textColor = UIColor.white
        self.sliderLabel.text = String(self.slider.value)

        // Assemble
        self.view.addSubview(self.orangeSquare)
        self.view.addSubview(self.slider)
        self.view.addSubview(self.sliderLabel)

        // Configure dynamic behaviours

        self.dynamicAnimator = UIDynamicAnimator(referenceView: self.view)
        self.gravityBehaviour = UIGravityBehavior(items: [self.orangeSquare])
        self.gravityBehaviour.gravityDirection = CGVector(dx: 0, dy: 0)

        // Configure boundaries
        let boundaries : UICollisionBehavior = UICollisionBehavior(items: [self.orangeSquare])
        boundaries.translatesReferenceBoundsIntoBoundary = true

        self.dynamicAnimator.addBehavior(self.gravityBehaviour)
        self.dynamicAnimator.addBehavior(boundaries)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func sliderValueDidChange() {
        // When the slider value changes, update the label text and the gravity vector
        self.sliderLabel.text = String((round(self.slider.value) * 10) / 10)
        self.gravityBehaviour.gravityDirection = CGVector(dx: 0, dy: CGFloat(-1 * self.slider.value))
    }

}

希望有所帮助。一切都好！

Answer 2

import UIKit

class ViewController: UIViewController {

    var dynamicAnimator : UIDynamicAnimator!
    var gravityBehaviour : UIGravityBehavior!
    var orangeSquare : UIView!
    var slider : UISlider!
    var sliderLabel : UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Subviews
        self.orangeSquare = {
            let oS : UIView = UIView(frame: CGRect(origin: CGPoint(x: (self.view.frame.width / 2) - 100, y: 500), size: CGSize(width: 200, height: 200)))
            oS.backgroundColor = UIColor.orangeColor()
            return oS
            }()

        self.slider = UISlider(frame: CGRect(origin: CGPoint(x: self.view.frame.width - 100, y: 100), size: CGSize(width: self.view.frame.width - 300, height: 150)))
        self.slider.addTarget(self, action: #selector(self.sliderValueDidChange), forControlEvents: UIControlEvents.AllTouchEvents)
        self.slider.minimumValue = -10
        self.slider.maximumValue = 10
        self.slider.value = 0

        self.sliderLabel = UILabel(frame: CGRect(origin: CGPoint(x: self.view.frame.width - 100, y: 200), size: CGSize(width : 50, height: 50)))
        self.sliderLabel.backgroundColor = UIColor.redColor()
        self.sliderLabel.textAlignment = NSTextAlignment.Center
        self.sliderLabel.textColor = UIColor.whiteColor()
        self.sliderLabel.text = String(self.slider.value)

        // Assemble
        self.view.addSubview(self.orangeSquare)
        self.view.addSubview(self.slider)
        self.view.addSubview(self.sliderLabel)

        // Configure dynamic behaviours

        self.dynamicAnimator = UIDynamicAnimator(referenceView: self.view)
        self.gravityBehaviour = UIGravityBehavior(items: [self.orangeSquare])
        self.gravityBehaviour.gravityDirection = CGVector(dx: 0.0, dy: 0.0)

        // Configure boundaries
        let boundaries : UICollisionBehavior = UICollisionBehavior(items: [self.orangeSquare])
        boundaries.translatesReferenceBoundsIntoBoundary = true

        self.dynamicAnimator.addBehavior(self.gravityBehaviour)
        self.dynamicAnimator.addBehavior(boundaries)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func sliderValueDidChange() {
        // When the slider value changes, update the label text and the gravity vector
        self.sliderLabel.text = String((round(self.slider.value) * 10) / 10)
        self.gravityBehaviour.gravityDirection = CGVector(dx: 0, dy: CGFloat(-1 * self.slider.value))
    }

}

滑块决定重力

2 个答案: