Swift UIImagePickerController 动态转换获取路径失败

Question

我正在尝试从 UIImagePicker 获取照片的路径，当我尝试获取它时得到的是 "Swift dynamic cast failed"。这是我的代码：

@IBAction func addPhotoButton(sender: AnyObject) {
    if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.SavedPhotosAlbum){

        imagePicker.delegate = self
        imagePicker.sourceType = UIImagePickerControllerSourceType.SavedPhotosAlbum;
        imagePicker.allowsEditing = true

        self.presentViewController(imagePicker, animated: true, completion: nil)
    }
}

在这里我找到了路径：

func imagePickerController(picker: UIImagePickerController!, didFinishPickingImage image: UIImage!, editingInfo: NSDictionary!){
    self.dismissViewControllerAnimated(true, completion: { () -> Void in
        var path: NSURL = editingInfo.valueForKeyPath("UIImagePickerControllerOriginalImage") as NSURL
        println(path)
    })
}

当我尝试获取 var 的值时应用程序崩溃 path

Answer 1

UIImagePickerControllerOriginalImage 键将 return UIImage 而不是所选图像的 NSURL。

如果你需要引用 url，你需要使用 UIImagePickerControllerReferenceURL 键。

更改您的以下代码：

var path: NSURL = editingInfo.valueForKeyPath("UIImagePickerControllerOriginalImage") as NSURL

至：

var path: NSURL = editingInfo.valueForKey("UIImagePickerControllerReferenceURL") as NSURL

UIImagePickerControllerOriginalImage

Specifies the original, uncropped image selected by the user.

The value for this key is a UIImage object.

UIImagePickerControllerReferenceURL

The Assets Library URL for the original version of the picked item.

After the user edits a picked item—such as by cropping an image or trimming a movie—the URL continues to point to the original version of the picked item.

The value for this key is an NSURL object.

引用UIImagePickerControllerDelegate Protocol Reference

Swift UIImagePickerController 动态转换获取路径失败

Swift UIImagePickerController dynamic cast failed in getting path

path

uiimagepickercontroller

ios

swift