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”。我希望用户通过一个滑块来确定值。
到目前为止这是我的代码:
import UIKit
class ViewController: UIViewController {
var orangeSquare: UIView?
var animator: UIDynamicAnimator?
override func viewDidLoad() {
super.viewDidLoad()
func sliderChanged(sender: AnyObject) {
var sliderValue = sender.value
}
//Create animation
let dim = CGRectMake(100, 500, 200, 100)
orangeSquare = UIView(frame: dim)
orangeSquare?.backgroundColor = UIColor.orangeColor()
//Add item to the screen
self.view.addSubview(orangeSquare!)
//Initialize the animator
animator = UIDynamicAnimator(referenceView: self.view)
//Add gravity
let gravity = UIGravityBehavior(items: [orangeSquare!])
let direction = CGVectorMake(0.0, sliderValue)
gravity.gravityDirection = direction
//Collision
let boundries = UICollisionBehavior(items: [orangeSquare!])
boundries.translatesReferenceBoundsIntoBoundary = true
//Add animations
animator?.addBehavior(boundries)
animator?.addBehavior(gravity)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
我有两个错误:
“对‘价值’的模糊使用”和
“使用未解析的标识符‘sliderValue’
如何将“sliderValue”转换为只有一个小数点的浮点?
最佳答案
你的代码少了一些东西。sliderValue是一个未解析的标识符,因为您只在sliderChanged中声明了它,但在viewDidLoad的主体中引用了它。另外,我认为您对value的使用是不明确的,因为您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!
您的代码缺少一个机制,该机制将滑块值的更改与重力行为的更改相链接。因此,我使用附加到滑块对象的显式目标实现了这一点。我还贴了一个标签,显示重力的大小。这是相当粗糙,但我认为它实现了你所期待的。
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))
}
}
希望能有所帮助。一切顺利!
关于ios - 滑块确定重力,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/39517053/