iOS Swift，无法使用捏合手势

Question

我有一个测试项目，它从文件中获取文本，将其添加到文本视图并显示它。我想添加一些手势，但似乎无法使其工作...... 这是相关代码：

class ViewController2: UIViewController, UIGestureRecognizerDelegate {

@IBOutlet var textview1: UITextView!

var pinchGesture = UIPinchGestureRecognizer()

override func viewDidLoad() {
    super.viewDidLoad()

    self.textview1.userInteractionEnabled = true
    self.textview1.multipleTouchEnabled = true

    self.pinchGesture.delegate = self
    self.pinchGesture = UIPinchGestureRecognizer(target: self, action: #selector(ViewController2.pinchRecognized(_:)))
    self.view.addGestureRecognizer(self.pinchGesture)
}


@IBAction func pinchRecognized(pinch: UIPinchGestureRecognizer) {
    self.textview1.addGestureRecognizer(pinchGesture)
    self.textview1.transform = CGAffineTransformScale(self.textview1.transform, pinch.scale, pinch.scale)
    pinch.scale = 1.0
}

有什么想法吗？遵循了几个教程，但 none 似乎有所帮助。代码在实际 iPhone...

上进行了测试

非常感谢

编辑解决方案：

@IBAction func pinchRecognized(pinch: UIPinchGestureRecognizer) {
    var pinchScale = pinchGesture.scale
    pinchScale = round(pinchScale * 1000) / 1000.0
    if (pinchScale < 1) {
        self.textview1.font = UIFont(name: self.textview1.font!.fontName, size: self.textview1.font!.pointSize - pinchScale)
        pinchScale = pinchGesture.scale
    } else {
        self.textview1.font = UIFont(name: self.textview1.font!.fontName, size: self.textview1.font!.pointSize + pinchScale)
        pinchScale = pinchGesture.scale
    }
}

感谢 nishith Singh

Answer 1

你在初始化前设置了self.pinchGesture的委托。

首先初始化 self.pinchGesture。
设置 delegate.

将self.pinchGesture添加到self.view

self.pinchGesture.delegate = self
self.pinchGesture = UIPinchGestureRecognizer(target: self, action:#selector(ViewController2.pinchRecognized(_:)))
self.view.addGestureRecognizer(self.pinchGesture)

Answer 2

尝试将手势识别器添加到 viewDidLoad 中的文本视图，而不是将其添加到 pinchRecognized 中。目前您正在将 pinchGesture 添加到文本视图后面的视图中，因此不会收到触摸

var pinchGesture = UIPinchGestureRecognizer()

使用此代码：

override func viewDidLoad() {
    super.viewDidLoad()
    
    self.textview1.userInteractionEnabled = true
    self.textview1.multipleTouchEnabled = true
    
    self.pinchGesture = UIPinchGestureRecognizer(target: self, action:#selector(pinchRecognized(_:)))
    self.textview1.addGestureRecognizer(self.pinchGesture)

    // Do any additional setup after loading the view.
}

@IBAction func pinchRecognized(_ pinch: UIPinchGestureRecognizer) {
    let fontSize = self.textview1.font!.pointSize*(pinch.scale)/2
    if fontSize > 12 && fontSize < 32{
        textview1.font = UIFont(name: self.textview1.font!.fontName, size:fontSize)
    }
}

您可能需要根据需要尝试使用最小和最大字体大小，目前最小字体大小为 12，最大字体大小为 32。

Answer 3

class ViewController2: UIViewController, UIGestureRecognizerDelegate {

@IBOutlet var textview1: UITextView!

var pinchGesture = UIPinchGestureRecognizer()

override func viewDidLoad() {
    super.viewDidLoad()

    self.textview1.userInteractionEnabled = true
    self.textview1.multipleTouchEnabled = true

    self.pinchGesture.delegate = self
    self.pinchGesture = UIPinchGestureRecognizer(target: self, action: "pinchRecognized:")
    self.view.addGestureRecognizer(self.pinchGesture)
}


func pinchRecognized(pinch: UIPinchGestureRecognizer) {
    self.textview1.addGestureRecognizer(pinchGesture)
    self.textview1.transform = CGAffineTransformScale(self.textview1.transform, pinch.scale, pinch.scale)
    pinch.scale = 1.0
}

Answer 4

您的代码确实有效。但可能不是你想要的方式。

最初您将手势识别器分配给视图控制器的视图。

但随后在该方法中，您向 UITextView 添加了相同的手势识别器。

所以它应该在 UITextView 上工作。手势识别器从视图控制器的视图中移除。手势识别器只能有一个目标。选择视图控制器的视图或文本视图。

Answer 5

let pinchGesture = UIPinchGestureRecognizer(target: self, action:#selector(self.pinchGesture))
func pinchGesture(sender: UIPinchGestureRecognizer){
sender.view?.transform = (sender.view?.transform)!.scaledBy(x:   sender.scale, y: sender.scale)
    sender.scale = 1
    print("pinch gesture")
}

iOS Swift，无法使用捏合手势

iOS Swift, cannot get pinch gesture to work

gestures

ios

swift