UIImagePickerController:自定义相机叠加位于默认控件的顶部？

import UIKit

class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建自定义相机叠加视图
        let overlayView = UIView(frame: self.view.bounds)
        overlayView.backgroundColor = UIColor.clear
        
        // 添加自定义控件到相机叠加视图
        let captureButton = UIButton(type: .custom)
        captureButton.frame = CGRect(x: (self.view.bounds.width - 100) / 2, y: self.view.bounds.height - 150, width: 100, height: 100)
        captureButton.setTitle("拍照", for: .normal)
        captureButton.addTarget(self, action: #selector(captureButtonTapped), for: .touchUpInside)
        overlayView.addSubview(captureButton)
        
        // 实例化UIImagePickerController对象
        let imagePicker = UIImagePickerController()
        imagePicker.sourceType = .camera
        imagePicker.cameraOverlayView = overlayView
        imagePicker.showsCameraControls = false
        imagePicker.delegate = self
        
        // 显示UIImagePickerController
        present(imagePicker, animated: true, completion: nil)
    }
    
    @objc func captureButtonTapped() {
        // 处理拍照按钮点击事件
        // 可以在这里调用UIImagePickerController的takePicture()方法拍照
    }
    
    // UIImagePickerControllerDelegate方法，处理拍照完成后的回调
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        // 处理拍照完成后的逻辑
        // 可以在这里获取拍摄的照片，并进行后续处理
        dismiss(animated: true, completion: nil)
    }
    
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        // 处理取消拍照的逻辑
        dismiss(animated: true, completion: nil)
    }
}