iOS14下用PHPickerViewController替换UIImagePickerController后选中照片不更新UI

• 未校验NSItemProvider是否支持加载UIImage类型，也没有处理加载错误逻辑，iCloud同步的照片、特殊格式资源会出现加载无返回的情况
• iOS 14部分小版本存在loadObject(ofClass: UIImage.self)回调不触发的已知兼容问题
• 资源加载闭包未对当前控制器做弱引用，极端情况下会出现循环引用导致UI更新逻辑不执行

替换原有代理实现代码为以下版本，适配iOS 14+的PHPicker加载逻辑，需先在文件顶部导入UniformTypeIdentifiers框架：

extension EditProfileController: PHPickerViewControllerDelegate {
    @available(iOS 14, *)
    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        picker.dismiss(animated: true)
        
        // 单选场景直接取第一个结果，多选可保留原有遍历逻辑
        guard let result = results.first else { return }
        let itemProvider = result.itemProvider
        
        // 先校验是否支持加载图片类型
        guard itemProvider.canLoadObject(ofClass: UIImage.self) else { return }
        
        itemProvider.loadObject(ofClass: UIImage.self) { [weak self] object, error in
            // 处理加载错误
            if let error = error {
                print("图片加载失败: \(error.localizedDescription)")
                // 可自行添加加载失败的用户提示逻辑
                return
            }
            
            guard let image = object as? UIImage else {
                // loadObject加载失败时用loadDataRepresentation兜底
                if itemProvider.hasItemConformingToTypeIdentifier(UTType.image.identifier) {
                    itemProvider.loadDataRepresentation(forTypeIdentifier: UTType.image.identifier) { data, _ in
                        guard let data = data, let image = UIImage(data: data) else { return }
                        DispatchQueue.main.async {
                            self?.profileImageView.image = image
                            self?.imageChanged = true
                        }
                    }
                }
                return
            }
            
            DispatchQueue.main.async {
                self?.profileImageView.image = image
                self?.imageChanged = true
            }
        }
    }
}

确认PHPicker初始化逻辑符合要求，避免配置错误导致加载失败：

// 正确的PHPicker初始化示例
var config = PHPickerConfiguration()
config.filter = .images // 限制只能选择图片
config.selectionLimit = 1 // 单选场景设置为1，多选可调整对应数值
let picker = PHPickerViewController(configuration: config)
picker.delegate = self
present(picker, animated: true)

内容的提问来源于stack exchange，提问作者safetotry