1个UIImagePickerController和2个按钮

我有一个UIImagePickerController和2个按钮。当我点击按钮1时,我想设置按钮1的图像。当我点击按键2时,我想要设置按钮2的图像。我已经使用UIImagePickerController成功地设置了按钮1的图片,但未能使用按钮2进行设置。下面是我的代码:

var whichButton: Int = 0

func displayImagePicker(){

    let imagePicker = UIImagePickerController()
    imagePicker.delegate = self
    imagePicker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
    imagePicker.allowsEditing = false

    self.presentViewController(imagePicker, animated: true, completion: nil)

}

@IBAction func chooseImageOne(sender: AnyObject) {

    displayImagePicker()

    whichButton = 1

}

@IBAction func chooseImageTwo(sender: AnyObject) {

    displayImagePicker()

    whichButton = 2

}

func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {

    self.dismissViewControllerAnimated(true, completion: nil)

    if whichButton == 1 {

        self.imageOne.setImage(image, forState: UIControlState.Normal)

    } else if whichButton == 2 {

        self.imageTwo.setImage(image, forState: UIControlState.Normal)

    }
}

正如你所看到的,我尝试使用var来跟踪我正在点击的按钮。我不确定我在didFinishPickingImage函数中所做的是正确的。我对斯威夫特很陌生,如果有人能透露一些信息,那真的很棒!提前谢谢