ios - ImageView 不会更新新图像

Question

我正在尝试从用户的手机中选择一张图片，并使用该图片更新图片 View 。

我遇到的问题是它不会更新图像。它确实到达那里，因为我添加了一个断点并且它击中了断点，并且 ImageView 可以更改图像，因为我在其他地方手动尝试更改它。

但是当我需要它时它拒绝工作。

我的 ImageView :

    lazy var profilePictureImageView: UIImageView = {
        let imageView = UIImageView()
        imageView.image = UIImage(named: "DefaultUser")
        imageView.translatesAutoresizingMaskIntoConstraints = false
        imageView.contentMode = .scaleAspectFill

        imageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleSelectProfilePicture)))
        imageView.isUserInteractionEnabled = true
        return imageView
    }()

通过在设备上选择照片来更新图像的代码:

import UIKit

extension ProfileVC: UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    func handleSelectProfilePicture() {
        let picker = UIImagePickerController()
        picker.delegate = self
        picker.allowsEditing = true
        present(picker, animated: true, completion: nil)
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
         var selectedImageFromPicker: UIImage?
         if let editedImage = info["UIImagePickerControllerEditedImage"] as? UIImage {
             selectedImageFromPicker = editedImage
         }
         else if let originalImage = info["UIImagePickerControllerOriginalImage"] as? UIImage {
             selectedImageFromPicker = originalImage
         }
        if let selectedImage = selectedImageFromPicker {
             profilePictureImageView.image = selectedImage
        }
        dismiss(animated: true, completion: nil)
    }

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

[编辑] 我发现的一件事是，如果我在具有不同 ImageView 的不同 VC 上尝试它，它会按预期工作。我能看到的两个 VC 之间唯一的主要区别是我希望它在上面工作但不会同时扩展“UIPickerViewDelegate”和“UIPickerViewDataSource”的那个。会不会有冲突？

Answer 1

试试这个，它对我有用:

DispatchQueue.main.async {
    profilePictureImageView.image = croppedImage
    profilePictureImageView.setNeedsDisplay()
}

本质上，您需要指定要通过以下方式更新图像

profilePictureImageView.setNeedsDisplay()