如何将图像加载到 iOS 应用程序中

Question

我正在尝试创建一个能够使用相机拍摄图像的应用程序，加载到UIImageView。当我重新启动应用程序时，我希望将照片加载到UIImageView，我该怎么做？

拍照：

@IBOutlet weak var p2Image: UIImageView!    
@IBAction func p2takePhoto(_ sender: Any) {  

    let image = UIImagePickerController()  
    image.delegate = self  
    image.sourceType = UIImagePickerControllerSourceType.camera  
    image.allowsEditing = false  
    self.present(image, animated : true){}  

}  

拍照后，我用UIImageView显示照片并保存照片的路径：

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {  
    if let image = info[UIImagePickerControllerOriginalImage] as? UIImage  
    {  
        p2Image.image = image  
        UserDefaults.standard.set(p2Image.image?.accessibilityPath, forKey: "p2ImagePath")  
    }  
    else  
    {  

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

每次打开我的应用程序时显示我的照片的代码：

override func viewDidAppear(_ animated: Bool) {  
    if let x = UserDefaults.standard.object(forKey: "p2ImagePath") as? String  
    {  
        p2Image.image = x  
    }  

但它不起作用，甚至无法构建，它说

p2Image.image = x（不能将字符串类型的值赋给 UIImage 类型）

我错过了什么吗？还是我用错了方法？

Answer 1

我终于解决了

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

    if let image = info[UIImagePickerControllerOriginalImage] as? UIImage
    {
        p2Image.image = image
        let saveImage = p2Image.image
        let imageData:NSData = UIImagePNGRepresentation(saveImage!)! as NSData

        UserDefaults.standard.set(imageData, forKey: "keyp2Image")
    }
    else
    {
        //error message
    }
    self.dismiss(animated: true, completion: nil)
}


override func viewWillAppear(_ animated: Bool) {


    if UserDefaults.standard.object(forKey: "keyp2Image") != nil
    {
    let data = UserDefaults.standard.object(forKey: "keyp2Image") as! NSData
    p2Image.image = UIImage(data: data as Data)
    }
}

Answer 2

将图像存储在 UserDefaults 中是个坏主意；更好的存储解决方案on the disk

这里

if let x = UserDefaults.standard.object(forKey: "p2ImagePath") as? String  
{  
    p2Image.image = x  
} 

您尝试将路径“p2ImagePath”处的内容转换为字符串，如果成功，请将其设置为您的图像视图；如果您希望它编译，请将其转换为 UIImage，但是，无论如何，您真正应该做的是将图像作为 NSData 存储在特定路径并改为存储

已编辑：

我错过了您的 accessabilityPath 并认为您正试图将图像准确存储在 UserDefaults :) 所以，你可以试试

if let x = UserDefaults.standard.object(forKey: "p2ImagePath") as? String  
{  
    p2Image.image = UIImage(contentsOfFile: x)
}