未调用 UIScrollViewDelegate 函数

Posted 2023-02-15

【中文标题】未调用 UIScrollViewDelegate 函数

【英文标题】：UIScrollViewDelegate functions not called

【发布时间】：2015-02-24 08:30:43

【问题描述】：

当我拖动它时，我的视图似乎在滚动（侧栏出现并四处移动），但我的委托函数没有触发。 问题：为什么不调用协议函数中的 println？ 作为背景，我试图在 Swift 中重写 https://github.com/bobmoff/ScrollKit，这就是 UIView 与 SKView 等混合的原因.

我的日志输出是：

852.0480.0完成viewDidLoad

代码是：

import UIKit
import SpriteKit
var kViewTransformChanged = "view transform changed"
var scene = GameScene()
var skView = SKView()
var clearContentView = UIView()

extension SKNode 
    class func unarchiveFromFile(file : NSString) -> SKNode? 
        if let path = NSBundle.mainBundle().pathForResource(file, ofType: "sks") 
            var sceneData = NSData(contentsOfFile: path, options: .DataReadingMappedIfSafe, error: nil)!
            var archiver = NSKeyedUnarchiver(forReadingWithData: sceneData)

            archiver.setClass(self.classForKeyedUnarchiver(), forClassName: "SKScene")
            let scene = archiver.decodeObjectForKey(NSKeyedArchiveRootObjectKey) as GameScene
            archiver.finishDecoding()
            return scene
         else 
            return nil
        
    


class GameViewController: UIViewController, UIScrollViewDelegate 

    override func viewDidLoad() 

        super.viewDidLoad()

        // Configure the view.
        skView = self.view as SKView
        skView.showsFPS = true
        skView.showsNodeCount = true

        /* Sprite Kit applies additional optimizations to improve rendering performance */
        skView.ignoresSiblingOrder = true

        /* Set the scale mode to scale to fit the window */
        scene.scaleMode = .AspectFill

        skView.presentScene(scene)

        var contentSize = skView.bounds.size
        contentSize.height *= 1.5
        contentSize.width *= 1.5
        scene.size = contentSize

        println(contentSize.height)
        println(contentSize.width)

        var scrollView = UIScrollView()
        scrollView.frame = skView.frame
        scrollView.contentSize = contentSize
        scrollView.delegate = self
        scrollView.maximumZoomScale = 3
        scrollView.minimumZoomScale = 1
        scrollView.indicatorStyle = UIScrollViewIndicatorStyle.White


        clearContentView.frame = CGRect(origin: CGPointZero, size: contentSize)

        clearContentView.backgroundColor = UIColor.clearColor()

        scrollView.addSubview(clearContentView)
        clearContentView.addObserver(self, forKeyPath: "transform", options: NSKeyValueObservingOptions(), context: &kViewTransformChanged)

        skView.addSubview(scrollView)

        //
        println("Finished viewDidLoad")
    


    func viewForZoomingInScrollView() -> UIView? 
        println("entering viewForZoomingInScrollView function")
        return self.view
    

    func scrollViewDidScroll() 
        println("entering scrollViewDidScroll function")
        adjustContent()
    

    // NOT SURE ABOUT THIS FUNCTION
    func adjustContent() 
        println("entering adjustContent function")
        NSLog("?")
        var scrollV = self.view as UIScrollView
        scene.setScale(scrollV.zoomScale)
        scene.position = scrollV.contentOffset
    

    func scrollViewDidZoom() 
        println("entering scrollViewDidZoom function")
        adjustContent()
    

    func scrollViewDidTransform() 
        println("entering scrollViewDidTransform function")
        adjustContent()
    

    func scrollViewDidEndZooming() 
        println("entering scrollViewDidEndZooming function")
        adjustContent()
    

    override func shouldAutorotate() -> Bool 
        return true
    

    override func supportedInterfaceOrientations() -> Int 
        if UIDevice.currentDevice().userInterfaceIdiom == .Phone 
            return Int(UIInterfaceOrientationMask.AllButUpsideDown.rawValue)
         else 
            return Int(UIInterfaceOrientationMask.All.rawValue)
        
    

    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        // Release any cached data, images, etc that aren't in use.
    

    override func prefersStatusBarHidden() -> Bool 
        return true
    

【参考方案1】：

您的UIScrollViewDelegate 函数实现与the documentation 中的声明不匹配。具体来说，您缺少 UIScrollView 参数。

例如，这个：

func scrollViewDidScroll() 
    println("entering scrollViewDidScroll function")
    adjustContent()

应该是：

func scrollViewDidScroll(scrollView: UIScrollView) 
    println("entering scrollViewDidScroll function")
    adjustContent()