如何在iOS Swift中将四舍五入的头像图片(从url字符串)设置为UIBarButton项目

guard let url = URL(string: "头像图片的URL字符串") else {
    return
}

URLSession.shared.dataTask(with: url) { (data, response, error) in
    if let error = error {
        print("下载图片数据时发生错误：\(error.localizedDescription)")
        return
    }
    
    if let data = data, let image = UIImage(data: data) {
        // 在这里进行下一步操作，将图片设置为UIBarButton项目
    }
}.resume()

guard let originalImage = image else {
    return
}

let size = CGSize(width: 30, height: 30) // 设置头像图片的大小
let scale = UIScreen.main.scale // 获取屏幕的缩放比例
let renderer = UIGraphicsImageRenderer(size: size)

let roundedImage = renderer.image { (context) in
    let rect = CGRect(origin: .zero, size: size)
    UIBezierPath(roundedRect: rect, cornerRadius: size.width/2).addClip()
    originalImage.draw(in: rect)
}

let roundedImageBarButtonItem = UIBarButtonItem(image: roundedImage, style: .plain, target: self, action: #selector(handleBarButtonItemTapped))
navigationItem.rightBarButtonItem = roundedImageBarButtonItem

@objc func handleBarButtonItemTapped() {
    // 处理导航栏按钮点击事件
}