9.Swift UIImagePickerController选取图片

IOS获取本机图片的方式比Android简单得多，而且代码很干净、简洁。

• 1.通过调用IOS提供好的UIImagePickerController去选取图片，同样也是一个Controller，需要我们通过presentViewController跳转。

• 2.如果要对UIImagePickerController选择的图片行为进行监听需要设置UIImagePickerController.delegate: protocol<UIImagePickerControllerDelegate, UINavigationControllerDelegate>?，可以看到这里需要实现两个协议，原来老版本中，只需要一个UIImagePickerControllerDelegate就只够了。

• 3.然后覆写UIImagePickerControllerDelegate.imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject])方法，就可以监听到选择的图片。

class ViewController: UIViewController,UINavigationControllerDelegate, UIImagePickerControllerDelegate  {

    @IBOutlet weak var iv: UIImageView!
    private var imagePC:UIImagePickerController!
    @IBAction func getImageBTonClick(sender: AnyObject) {
        // 实例化UIImagePickerController
        self.imagePC = UIImagePickerController()
        // 设置UIImagePickerController数据源为：本机图片库
        self.imagePC.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        // 设置实现协议的类
        self.imagePC.delegate = self
        self.presentViewController(self.imagePC, animated: true, completion: nil)
    }

    /** UIImagePickerControllerDelegate.imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject])

        对UIImagePickerController选择图片监听

     **/
    func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {
        self.iv.image = image
        // 关闭UIImagePickerController
        picker.dismissViewControllerAnimated(true, completion: nil)
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

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

}