如何在另一个图像上分层

Question

我的代码在下面的工作方式中，但是框架不是对称的，我正在使用2个图像let bottomImage和let frame，而应该只使用let框架。给你一个例子，看看下面我创建的图像。框架应代替黑色边框。

   @IBAction func Mask(_ sender: Any) {
    let bottomImage:UIImage = UIImage(named: "backdropd")!


    let frame:UIImage = UIImage(named: "ff")!

    let newSize = CGSize(width: bottomImage.size.width, height: bottomImage.size.height  )
    let newSize2 = CGSize(width: bottomImage.size.width, height: bottomImage.size.height)
    UIGraphicsBeginImageContextWithOptions(newSize, false, bottomImage.scale)
    let left:UIImage = imageTake.image!
    left.draw(in: CGRect(x: newSize2.width/7,y: newSize2.height/8.9,width: newSize2.width/1,height:   newSize2.height/1.29), blendMode:CGBlendMode.normal, alpha:1.0)



    frame.draw(in: CGRect(x: 0,y: 0,width: newSize2.width,height:   newSize2.height), blendMode:CGBlendMode.normal, alpha:1.0)

    let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()

    imageTake.image = newImage

}