ios - iOS swift 拖动2个元素

Question

请在下面找到我在同一 UI 中拖动 2 个元素的代码，但似乎不适用于 2 个元素，当我从一个元素开始时一切正常。

当我添加第二个元素时，我在应用程序委托(delegate)中遇到此错误:

libc++abi.dylib: terminating with uncaught exception of type NSException

你们有更好的练习吗？

import UIKit

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()

    let label = UILabel(frame:CGRectMake(self.view.bounds.width / 4 - 100, self.view.bounds.height / 2 - 50, 200, 100))
    let label2 = UILabel(frame:CGRectMake(self.view.bounds.width / 1 - 200, self.view.bounds.height / 2 - 50, 200, 100))
    label.text = "Drag me!"
    label.textAlignment = NSTextAlignment.Center
    self.view.addSubview(label)

    label2.text = "drag me2!"
    label2.textAlignment = NSTextAlignment.Center
    self.view.addSubview(label2)

    let gesture = UIPanGestureRecognizer(target: self, action: Selector("wasDragged"))
    label.addGestureRecognizer(gesture)

    label.userInteractionEnabled = true


    let gesture2 = UIPanGestureRecognizer(target: self, action: ("wasDragged2"))
    label2.addGestureRecognizer(gesture2)
    label2.userInteractionEnabled = true


}

func wasDragged(gesture: UIPanGestureRecognizer) {

    print("was dragged")

}

func wasDragged2(gesture2: UIPanGestureRecognizer) {

    print("was draged2")



}


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

}

Answer 1

您的操作选择器“wasDragged”和“wasDragged2”是错误的。这些不是您的函数的名称。函数的名称为 "wasDragged:" 和 "wasDragged2:"(请注意每个字符串名称末尾的冒号)。