一、启用相册[picker.sourceType = .photoLibrary]

//检测相册访问权限
        //info.plist里开启Photo、Camera的权限
        if indexPath.row == 0 {
            guard UIImagePickerController.isSourceTypeAvailable(.photoLibrary) else { return }
            
            //实例化一个UIImagePickerController对象
            //属性是：不允许编辑，来源为相册，以模态视图弹出
            let picker = UIImagePickerController()
            picker.allowsEditing = false
            picker.sourceType = .photoLibrary
            self.present(picker, animated: true, completion: nil)
            
        }

二、启用摄像头[picker.sourceType = .camera]

//检测相册访问权限
        //info.plist里开启Photo、Camera的权限
        if indexPath.row == 0 {
            guard UIImagePickerController.isSourceTypeAvailable(.photoLibrary) else { return }
            
            //实例化一个UIImagePickerController对象
            //属性是：不允许编辑，来源为相册，以模态视图弹出
            let picker = UIImagePickerController()
            picker.allowsEditing = false
            picker.sourceType = .camera
            self.present(picker, animated: true, completion: nil)
            
        }

三、获取相册中的图片

3.1、之前只是能够访问，如果要获取图片[与相册互动]，需要遵守两个协议<UIImagePickerControllerDelegate、UINavigationControllerDelegate>

3.2、当用户从相册选择一张图后，会触发如下方法，实现该方法，可从方法的参数中取回图片

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
  
        //从info字典中，查询"原始图像"
        coverImageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage
        //平铺、裁边
        coverImageView.contentMode = .scaleAspectFill
        coverImageView.clipsToBounds = true
        //视图自退场
        dismiss(animated: true, completion: nil)      
    }

四、补充

别忘了设置代理哟，只有设置了代理，才可实现代理的方法

 picker.delegate = self