'Binder<UIImage?>' 类型的值没有成员 'bind'答案

【问题标题】：Value of type 'Binder<UIImage?>' has no member 'bind''Binder<UIImage?>' 类型的值没有成员 'bind'
【发布时间】：2019-03-12 06:31:46
【问题描述】：

我想将我的 ImageView 绑定到 viewModel 以将我选择的图像保存到 Core Data。

我的代码如下所示：

class FoodViewModel: FoodViewModelType {
    var foodImage: BehaviorRelay<UIImage?>
    //... another code
}

我的控制器：

class NewFoodViewController: UIViewController {
    @IBOutlet weak var foodImageView: UIImageView!

    override func viewDidLoad() {
       //... another code
       self.foodImageView.rx.image.bind(to: foodViewModel.foodImage).disposed(by: self.disposeBag)
    }
}

我得到错误：

Binder 没有成员“绑定”

如何通过良好的 MVVM 实践将我的图像保存到 Core Data？

更新

我在视图控制器中选择照片：

func chooseImagePickerAction(source: UIImagePickerController.SourceType) {
    if UIImagePickerController.isSourceTypeAvailable(source) {
        let imagePicker = UIImagePickerController()
        imagePicker.sourceType = source
        imagePicker.delegate = self
        self.present(imagePicker, animated: true, completion: nil)
    }
}

@objc func foodImageViewTapped(_ sender: AnyObject) {
    let alertController = UIAlertController(title: "Photo path", message: nil, preferredStyle: .actionSheet)

    let cameraAction = UIAlertAction(title: "Camera", style: .default) { (action) in
        self.chooseImagePickerAction(source: .camera)
    }

    let photoLibAction = UIAlertAction(title: "Photo", style: .default) { (action) in
        self.chooseImagePickerAction(source: .photoLibrary)
    }

    let cancelAction = UIAlertAction(title: "Cancel", style: .default)

    alertController.addAction(cameraAction)
    alertController.addAction(photoLibAction)
    alertController.addAction(cancelAction)

    self.present(alertController, animated: true, completion: nil)
}

extension NewFoodViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

        let info = convertFromUIImagePickerControllerInfoKeyDictionary(info)

        foodImageView.image = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey.originalImage)] as? UIImage
        foodImageView.contentMode = .scaleAspectFill

        dismiss(animated: true, completion: nil)
    }

    private func convertFromUIImagePickerControllerInfoKeyDictionary(_ input: [UIImagePickerController.InfoKey: Any]) -> [String: Any] {
        return Dictionary(uniqueKeysWithValues: input.map {key, value in (key.rawValue, value)})
    }

    private func convertFromUIImagePickerControllerInfoKey(_ input: UIImagePickerController.InfoKey) -> String {
        return input.rawValue
    }
}

在 viewDidLoad 中（无图片）：

saveNewFoodBarButtonItem.rx.tap.subscribe(onNext: { [weak self] _ in
    guard let self = self else { return }

    let foodViewModel = FoodViewModel()

    self.foodQuantityTypeTextField.rx.text.bind(to: foodViewModel.foodQuantityType).disposed(by: self.disposeBag)
    self.foodShelfLifeTextField.rx.text.bind(to: foodViewModel.foodShelfLife).disposed(by: self.disposeBag)
    self.foodCategoryTextField.rx.text.bind(to: foodViewModel.foodCategoryId).disposed(by: self.disposeBag)
    self.foodQuantityTextField.rx.text.bind(to: foodViewModel.foodQuantity).disposed(by: self.disposeBag)
    self.foodNameTextField.rx.text.bind(to: foodViewModel.foodName).disposed(by: self.disposeBag)

    foodViewModel.saveNewFood(fridgeViewModel: self.fridgeViewModel!)

    self.dismiss(animated: true)
}).disposed(by: disposeBag)

【问题讨论】：

您不应该在 viewModel 中下载图像并使用 foodImage.bind(to: foodImageView.rx.image).disposed(by: self.disposeBag) 将其绑定到视图控制器中的 imageView
我想从选定的用户图像（来自 iPhone 照片库）中创建新食物。
向我们展示将图像插入 UIImageView 的代码（如果您想这样做）。
我正在更新我的问题。添加代码

标签： ios swift core-data data-binding rx-swift

【解决方案1】：

UIImageView 是不可绑定的，因为它是一个输出视图，而不是一个输入视图，也就是说，你将东西推入其中，它不会将东西推出。

为了将图像发送到您的视图模型，您需要在将图像推送到 UIImageView 时执行此操作。

【讨论】：