Swift 中的 UIImagePickerController 图像答案

【问题标题】：UIImagePickerController image in SwiftSwift 中的 UIImagePickerController 图像
【发布时间】：2017-04-14 19:11:56
【问题描述】：

我在我的程序中使用 UIImagePickerController，它有效地改变了我添加的图像视图的图像。但是，每当我重新启动此应用程序并返回主屏幕时，它会自动重置为我之前使用的默认图像，而不是用户选择的图像。我怎样才能让它记录上次使用的图像，并在每次程序启动时重新加载它？

 var imagePicker = UIImagePickerController()
 func chooseImage(_ sender: Any) { //function called with button press

    let imagePickerController = UIImagePickerController()
    imagePickerController.delegate = self
    imagePickerController.allowsEditing = true

    let actionSheet = UIAlertController(title: "Photo Source", message: "Choose a source", preferredStyle: .actionSheet)

    actionSheet.addAction(UIAlertAction(title: "Camera", style: .default, handler: { (action:UIAlertAction) in

        if UIImagePickerController.isSourceTypeAvailable(.camera) {
            imagePickerController.sourceType = .camera
            self.present(imagePickerController, animated: true, completion: nil)
        }else{
            print("Camera not available")
        }


    }))

    actionSheet.addAction(UIAlertAction(title: "Photo Library", style: .default, handler: { (action:UIAlertAction) in
        imagePickerController.sourceType = .photoLibrary
        self.present(imagePickerController, animated: true, completion: nil)
    }))

    actionSheet.addAction(UIAlertAction(title: "Default", style: .default, handler: { (action:UIAlertAction) in
        self.avatarImageView.image = UIImage(named: "Avatar.png")


    }))

    actionSheet.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))

    self.present(actionSheet, animated: true, completion: nil)


}

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    let image = info[UIImagePickerControllerEditedImage] as! UIImage

    avatarImageView.image = image

    picker.dismiss(animated: true, completion: nil)



}

func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
    picker.dismiss(animated: true, completion: nil)
}

【问题讨论】：

我假设您的意思是实际的应用重启（即内存不足），而不是仅仅点击主屏幕然后重新启动应用？
您需要将图像保存在某处，并在您的应用下次启动时加载它
@LeoDabus 我该怎么做？请指导我。
另存为 jpeg stackoverflow.com/questions/29726643/…
你需要有某种持久层。你可以使用数据库、Core Data 甚至 NSUserDefaults。稍后我会尝试整理一个示例。

标签： ios swift uiimage uiimagepickercontroller

【解决方案1】：

由于应用程序内存不足，您需要某种持久性机制来保存图像。最简单的方法是将图像存储在UserDefaults 中。这可以这样完成：

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {

    let image = info[UIImagePickerControllerEditedImage] as! UIImage
    avatarImageView.image = image
    UserDefaults.standard.set(UIImagePNGRepresentation(image), forKey: "avatarImage")    

    picker.dismiss(animated: true, completion: nil)
}

然后，当您重新打开应用程序时，您需要检查您之前是否在UserDefaults 中保存了头像图像并从那里加载：

// Could be in viewDidLoad or wherever else you load your image
override func viewDidLoad() {

    if let imageData = UserDefaults.standard.object(forKey: "avatarImage") as? Data {
        avatarImageView.image = UIImage(data: imageData)
    }
}

【讨论】：