如何在Xcode中将一张图片叠加到另一张图片上？

Question

我正在尝试制作一个应用程序，用户可以从他们的图像库中选择一张图片作为背景，然后选择他们也可以从他们的（照片）库中选择的徽标...

目前为止，我还没有找到可以帮助我的教程，主要是因为用户必须能够设置自己的图像而不是默认图像。 此外，你们中有人知道我如何拥有多个UIImagePickerControllers，因为这段代码同时影响两个图像而不是每个选择器一个吗？

我使用/拥有的：
我使用Swift
我使用xcode 7.0.1
这是我目前使用的故事板。

我的swift文件：

class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

  @IBOutlet weak var logo: UIImageView!
  @IBOutlet weak var bgimg: UIImageView!

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

  @IBAction func selectbg(sender: AnyObject) {
    let bgPicker = UIImagePickerController()
    bgPicker.delegate = self
    bgPicker.sourceType = .PhotoLibrary
    self.presentViewController(bgPicker, animated: true, completion: nil)
  }

  @IBAction func selectlogo(sender: AnyObject) {
    let logoPicker = UIImagePickerController()
    logoPicker.delegate = self
    logoPicker.sourceType = .PhotoLibrary
    self.presentViewController(logoPicker, animated: true, completion: nil)
  }

  func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {
    logo.image = image
    bgimg.image = image
    self.dismissViewControllerAnimated(false, completion: nil)
  }


  @IBAction func addImage(sender: AnyObject) {

    let ActionAlert = UIAlertController(title: nil, message: "What image do you want to add/edit?", preferredStyle: .ActionSheet)

    let bgimage = UIAlertAction(title: "Background", style: .Default, handler: { (Alert:UIAlertAction!) -> Void in
        print("Edit background image")
    })
    let logo = UIAlertAction(title: "Logo", style: .Default) { (Alert:UIAlertAction!) -> Void in
        print("Edit logo")
    }
    let cancel = UIAlertAction(title: "Cancel", style: .Cancel) { (Alert:UIAlertAction!) -> Void in
        print("remove menu")
    }

    ActionAlert.addAction(bgimage)
    ActionAlert.addAction(logo)
    ActionAlert.addAction(cancel)

    self.presentViewController(ActionAlert, animated: true, completion: nil)
}

}

如果我的问题不够清晰，请随时要求更多信息。

- Jenoah Kers

Answer 1

创建两个 UIImageView，为每个图像创建一个，并将前景图像添加为父视图的子视图。

类似这样的代码：

let bgimg = UIImage(named: "image-name") // The image used as a background
let bgimgview = UIImageView(image: bgimg) // Create the view holding the image
bgimgview.frame = CGRect(x: 0, y: 0, width: 500, height: 500) // The size of the background image

let frontimg = UIImage(named: "front-image") // The image in the foreground
let frontimgview = UIImageView(image: frontimg) // Create the view holding the image
frontimgview.frame = CGRect(x: 150, y: 300, width: 50, height: 50) // The size and position of the front image

bgimgview.addSubview(frontimgview) // Add the front image on top of the background

- Mate Hegedus

---

很好。谢谢你的回答！ - dinesharjani

Answer 2

这里是将页脚图像合并到原始图像的示例代码。

extension UIImage{
    func merge(mergewith:UIImage) -> UIImage {
        
        UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
        let actualArea = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        let mergeArea = CGRect(x: 0, y: size.height - mergewith.size.height, width: size.width, height: mergewith.size.height)
        self.draw(in: actualArea)
        mergewith.draw(in: mergeArea)
        let merged = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return merged
    }
}

- Jyothis Raj