29.iPhone距离传感器的简单使用

1.实现代码

[code]import UIKit
import CoreMotion

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func viewWillAppear(animated: Bool) {
        // 1.打开距离传感器
        UIDevice.currentDevice().proximityMonitoringEnabled = true

        // 2.设置一个通知, 一旦距离传感器被使用, 就调用自定义的proximatyChanged方法
        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("proximatyChanged"), name: UIDeviceProximityStateDidChangeNotification, object: nil)
    }

    // 3.自定义proximatyChanged方法
    func proximatyChanged() {
        print(">>>>>")
        print("\(UIDevice.currentDevice().proximityState)")
    }

    // 4.关掉页面之后, 把通知删除
    override func viewDidDisappear(animated: Bool) {
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

2.最终效果