如何设置UIToolbar的样式,使其看起来像标准的iPhone相机工具栏？

let toolbar = UIToolbar(frame: CGRect(x: 0, y: 0, width: view.bounds.width, height: 44))

toolbar.barStyle = .default

toolbar.backgroundColor = UIColor(red: 0.95, green: 0.95, blue: 0.95, alpha: 1.0)

let barButtonItem = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(doneButtonTapped))

toolbar.setItems([barButtonItem], animated: false)

view.addSubview(toolbar)

@objc func doneButtonTapped() {
    // 处理点击事件
}