防止在 UIImagePickerController 中选择同一张照片两次

Question

如何防止用户在 UIImagePickerContoroller 中选择相同的图像两次以避免重复？

我试着用 URLReference 来做，但它不起作用，所以我猜它不是这样。

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

    if let url = info[UIImagePickerControllerReferenceURL] as? NSURL{
        if photosURL.contains(url){
             Utilities.showMessage(message: "photo Uploaded already", sender: self, title: ErrorTitle.FRIENDS, onDismissAction: nil)
        } else {
            if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage {
                photos.append(pickedImage)
            }
        }
    }
    dismiss(animated: true, completion: nil)
}

谢谢，

Answer 1

您似乎没有将 url 附加到 photosURL？试试这个：

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

if let url = info[UIImagePickerControllerReferenceURL] as? NSURL{
    if photosURL.contains(url){
         Utilities.showMessage(message: "photo Uploaded already", sender: self, title: ErrorTitle.FRIENDS, onDismissAction: nil)
    } else {
        photosURL.append(url)
        if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage {
            photos.append(pickedImage)
        }
    }
}
dismiss(animated: true, completion: nil)
}

Answer 2

您还应该考虑先执行 picker.dismiss，然后再对图像执行其他逻辑。这样，您就可以防止用户多次点击图像并多次调用委托函数。

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    guard !picker.isBeingDismissed else {
        return
    }
    picker.dismiss(animated: true) {
        if let pickedImage = (info[UIImagePickerController.InfoKey(rawValue: UIImagePickerController.InfoKey.originalImage.rawValue)] as? UIImage) {
            // do stuff with the picked image
            print("Uesr picked an image \(pickedImage)")
        }
    }
}

Answer 3

swift 4

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

    let info = convertFromUIImagePickerControllerInfoKeyDictionary(info)

    if let capturedImage = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey.originalImage)] as? UIImage {
        // do stuff
    }

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

防止在 UIImagePickerController 中选择同一张照片两次

prevent picking the same photo twice in UIImagePickerController

uiimagepickercontroller

ios

swift

swift3