swift - 让可拖动的 UIImage 移回原点位置

Question

编辑:我能够以某种方式更改代码，使程序不再崩溃。但是，代码运行只剩下一个小问题:

正如您在我的控制台输出中看到的那样，origin2 的坐标与 origin 1 中的坐标不同。

origin1: (268.0, 241.0) origin2: (116.0, 323.0) sender view center: Optional((146.5, 397.0))

所以我需要从 viewDidLoad() 获取 imageOrigin1-values 并在 im func handlePan(sender:UIPanGestureRecognizer) 中使用它们。我只是不知道该怎么做...

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var image: UIImageView!
    @IBOutlet weak var correctField: UIImageView!

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

    }

    override func viewDidLoad() {
        super.viewDidLoad()

        let imageOrigin1 = image.frame.origin

        print("origin1: \(imageOrigin1)")
    }

    @IBAction func handlePan(sender:UIPanGestureRecognizer) {

        let imageOrigin2 = image.frame.origin

        let translation = sender.translationInView(self.view)

        if let view = sender.view {
            view.center = CGPoint(x:view.center.x + translation.x,
                                  y:view.center.y + translation.y)
        }

        if sender.state == UIGestureRecognizerState.Ended {

            if correctField.frame.contains(sender.view!.center){
                print("Correct")
                sender.setTranslation(CGPointZero, inView: self.view)
            } else{
                    print("origin2: \(imageOrigin2)")
                    print("sender view center: \(sender.view?.center)")
                //sender.view?.center = imageOrigin
            }
        }
    }
}

Answer 1

我自己解决了这个问题，添加了一个新类并通过 set 和 get 方法传递变量:

类(class):

import UIKit

class Origin {

var positionOrigin: CGPoint!

    func setImageOrigin(Image: UIImageView) {
        positionOrigin = Image.center
    }

    func getImageOrigin() -> CGPoint {
        return positionOrigin
    }
}

查看 Controller :

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var correctField: UIImageView!
    @IBOutlet weak var image: UIImageView!

    var imageOrigin = Origin()

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

    }

    override func viewDidLoad() {
        super.viewDidLoad()

        imageOrigin.setImageOrigin(image)

    }

    @IBAction func handlePan(sender:UIPanGestureRecognizer) {

        let translation = sender.translationInView(self.view)

        if let view = sender.view {
            view.center = CGPoint(x:view.center.x + translation.x,
                                  y:view.center.y + translation.y)
            sender.setTranslation(CGPointZero, inView: self.view)

        }

        if sender.state == UIGestureRecognizerState.Ended {

            if correctField.frame.contains(sender.view!.center){
                print("Correct")

            } else{

                image.center = imageOrigin.getImageOrigin()

            }
        }
    }
}