使用本地话的error
// 弹框网络不行
let alert = UIAlertController(title: "⚠️", message: err?.localizedDescription, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "ok", style: .default, handler: { (action:UIAlertAction) in
}))
self.present(alert, animated: true, completion: nil)
// 异步 到主线程
DispatchQueue.main.async {
}
