ios - swift ios 什么时候需要使用 mediaTypes kUTTypeImage

Question

我的应用程序中有一个图像选择器，您可以在其中从相机胶卷中选择图像或拍摄新照片，然后将图像上传到我的后端服务器。

但是环顾其他人的代码，我发现有些人使用这个: imagePickerController.mediaTypes = [kUTTypeImage as String]

为什么要设置mediaTypes为kUTTypeImage？

我没有在下面的代码中使用它，但一切仍然正常

我通过 UIAlertController 选择像这样的图像:

//Check if camera exist
        if UIImagePickerController.isSourceTypeAvailable(.Camera) {
            let cameraAction = UIAlertAction(title: "Take a photo", style: .Default) { (action) in
                self.imagePicker.sourceType = .Camera
                self.imagePicked = 1
                self.presentViewController(self.imagePicker, animated: true, completion: nil)

            }

            alertController.addAction(cameraAction)
        }

        //Check if photo lib exist
        if UIImagePickerController.isSourceTypeAvailable(.PhotoLibrary) {
            let photosLibraryAction = UIAlertAction(title: "Pick image", style: .Default) { (action) in
                self.imagePicker.sourceType = .PhotoLibrary
                self.imagePicked = 1
                self.presentViewController(self.imagePicker, animated: true, completion: nil)

            }
            alertController.addAction(photosLibraryAction)
        }

然后我得到图像:

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


            if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage {
                //Change aspect when not dummy image
                self.bigImage.contentMode = .ScaleAspectFill
                self.bigImage.clipsToBounds = true
                self.bigImage.image = pickedImage

Answer 1

kUTTypeImage 实际上是 mediaTypes 属性的默认值。它指出，只能选择静止图像。如果您接受此默认值，则无需在代码中显式设置它。

这是文档:https://developer.apple.com/reference/uikit/uiimagepickercontroller/1619173-mediatypes