如何将xib视图添加到视图控制器swift 3

import UIKit

class YourViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 加载xib文件
        if let customView = Bundle.main.loadNibNamed("YourXibFileName", owner: self, options: nil)?.first as? UIView {
            // 将xib视图添加到视图控制器的视图中
            self.view.addSubview(customView)
            
            // 设置xib视图的约束
            customView.translatesAutoresizingMaskIntoConstraints = false
            customView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
            customView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
            customView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
            customView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
        }
    }
}

let viewController = YourViewController()
self.present(viewController, animated: true, completion: nil)