ios – 在Swift导入扩展文件

我在 Swift中为UIView创建一个扩展名.任何人都知道如何将该文件导入到我的UIViewController？

我想在控制器文件中导入扩展文件,这样我可以重新使用扩展文件.例如这样的结构：

UIViewExtension.swift

import UIKit

extension UIView {
    var myVar : Float {
        get {
            return myVar
        }
        set (newMyVar) {
            myVar = newMyVar
        }
    }
}

ViewController.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view,typically from a nib.
        var squareView: UIView = UIView(frame: CGRect(x: 0,y: 0,width: 200,height: 200))

        squareView.myVar = 50

        self.view.addSubview(squareView)
        println("Offset: \(squareView.myVar)")
    }
}

这是编译器给出的错误：

命令/Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift失败,退出代码为254

warning: attempTing to access 'myVar' within its own getter
  return myVar
         ^

import UIKit

extension UIView {
  var myVar : Float {
  get {
    return 0
  }
  set {
  }
  }
}