private async void DeleteClick(object s, RoutedEventArgs e)
        {
            Msgbox msgbox = new Msgbox();
            string name   = ((Database.Data)((ListBoxItem)this.FindControl <ListBox>("list").SelectedItem).DataContext).formula;

            msgbox.init("将删除 \"" + name + "\"\n是否确认?\n此操作不可撤回!");
            await msgbox.ShowDialog(this);

            if (!msgbox.exitNormally)
            {
                return;
            }
            this.FindControl <ListBox>("list").SelectedItem = null;
            // this.FindControl<ListBox>("list").Items = new List<ListBoxItem>().ToImmutableArray();
            this.FindControl <ListBox>("list").Items     = Restore.db.Delete(name);
            this.FindControl <TextBox>("Searchbox").Text = "";
        }
        private async void UpdateClick(object sender, RoutedEventArgs e)
        {
            try
            {
                // 由于软件的主体用户是中国大陆用户,所以使用 Gitee。
                WebResponse response = WebRequest.Create("https://gitee.com/HCl-10/chemdb/raw/main/Database.db").GetResponse();
                Stream      stream   = response.GetResponseStream();
                string      ver      = "";
                int         ch       = stream.ReadByte();
                while (ch != 0)
                {
                    ver += (char)ch;
                    ch   = stream.ReadByte();
                }
                stream.Close();
                if (ver == Restore.db.version)
                {
                    this.FindControl <Button>("UpdateButton").Content = "您的数据库是最新版本";
                    return;
                }
                Msgbox msgbox = new Msgbox();
                msgbox.Title = "更新";
                msgbox.init("您的数据库不是最新版本。\n是否更新?");
                await msgbox.ShowDialog(this);

                if (!msgbox.exitNormally)
                {
                    return;
                }
                bool completed = false;
                response = WebRequest.Create("https://gitee.com/HCl-10/chemdb/raw/main/Database.db").GetResponse();
                BufferedStream buff    = new BufferedStream(response.GetResponseStream(), 1048576);
                long           Dloaded = 0;
                Thread         thread  = new Thread(() =>
                {
                    BufferedStream wr = new BufferedStream(File.Open("Database.db", FileMode.Create, FileAccess.Write, FileShare.Write), 1048576);
                    int bt            = buff.ReadByte();
                    while (bt != -1)
                    {
                        wr.WriteByte((byte)bt);
                        bt = buff.ReadByte(); ++Dloaded;
                    }
                    wr.Close();
                    buff.Close();
                    completed = true;
                });
                thread.Start();
                while (!completed)
                {
                    this.FindControl <Button>("UpdateButton").Content = "下载中,已下载:" + Dloaded.ToString("N0");
                    Thread.Sleep(100);
                }
                this.FindControl <Button>("UpdateButton").Content = "重启程序以完成更新";
            }
            catch (Exception ex)
            {
                Msgbox msgbox = new Msgbox();
                msgbox.Title = "错误";
                msgbox.init(ex.Message);
                await msgbox.ShowDialog(this);
            }
        }