ios - 如何在 TouchesBegan Swift 中添加第二个接触点

Question

我为三个 UIImageView 编写了一个 touchesMoved 函数，我想添加一个函数，让我使用多个 touchPoint 来移动 UIImageViews，但我不太确定该怎么做，如果有一点帮助会很棒。

import UIKit

class ViewController: UIViewController {

var attachment: UIAttachmentBehavior?
var location = CGPoint(x: 0, y: 0)

@IBOutlet var Ball3: UIImageView!
@IBOutlet var Ball2: UIImageView!
@IBOutlet var Ball1: UIImageView!
@IBOutlet var Floor: UIImageView!


override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {

    let touch2 = touches.first as UITouch!
    let touch = touches.first as UITouch!
    location = touch.locationInView(self.view)
    location = touch2.locationInView(self.view)

    if CGRectContainsPoint(Ball1.frame,location)
    {
        attachment = UIAttachmentBehavior(item: Ball1, attachedToAnchor: location)
        animator!.addBehavior(attachment!)
    }

    if CGRectContainsPoint(Ball2.frame,location)
    {
        attachment = UIAttachmentBehavior(item: Ball2, attachedToAnchor: location)
        animator!.addBehavior(attachment!)
    }

    if CGRectContainsPoint(Ball3.frame,location)
    {
        attachment = UIAttachmentBehavior(item: Ball3, attachedToAnchor: location)
        animator!.addBehavior(attachment!)
    }
}

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {

    let touch2 = touches.first as UITouch!
    location = touch2.locationInView(self.view)
    let touch = touches.first as UITouch!
    location = touch.locationInView(self.view)

    if attachment != nil
    {
        attachment!.anchorPoint = location
    }
}

override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {

    if animator != nil && attachment != nil
    {
        self.attachment == nil
        animator!.removeBehavior(self.attachment!)
    }
}

Answer 1

如果你给每个球一个UIPanGestureRecognizer ，然后他们将独立运作。给定一个手势识别器，您可以使用它的 locationInView(_:) 或 translationInView(_:) 方法来获取偏移量(和 view属性以获取它所附加的 View )。

我建议阅读 Event Handling Guide .