presentViewController如何显示视图？

Question

我很好奇presentViewController对第一个参数 imagePickerController 的处理方式。鉴于我分配imagePickerController属性的方式，presentViewController是否会使用所有这些信息来显示视图？

@IBAction func imageFromPhotoLibrary(sender: UITapGestureRecognizer) {
    // Hide the keyboard.
    myTextField.resignFirstResponder()

    // UIImagePickerController is a view controller that lets a user pick media from their photo library.
    let imagePickerController = UIImagePickerController()

    // Only allow photos to be picked, not taken.
    imagePickerController.sourceType = .PhotoLibrary

    // Make sure ViewController is notified when the user picks an image.
    imagePickerController.delegate = self

    presentViewController(imagePickerController, animated: true, completion: nil)
}

Answer 1

presentViewController不会使用任何选项。您传入的imagePickerController将使用这些选项。

由于Apple API设计得非常好，presentViewController做了一件事（SRP），并完全按照它的说法做了...... 提供了传递它的视图控制器。

imagePickerController负责控制图像选择器的视图。