更新签入目标-C?来自C#

我正在将我在C上编写的一个程序移植到Cocoa,我正在尝试找出如何使用XML联机访问我的网站,获取文件并对其进行解析,然后比较版本并弹出一个消息框,询问是否要打开浏览器以进入更新页。

以下是C#的代码:

 public void CheckVersion()
    {
        Version newVersion = null;
        string url = "";
        string newfeatures = "";
        try
        {
            string xmlURL = "http://myurl.com/version.xml";
            XmlRead = new XmlTextReader(xmlURL);
            XmlRead.MoveToContent();
            string elementName = "";
            if ((XmlRead.NodeType == XmlNodeType.Element) &&
                (XmlRead.Name == "myProgram"))
            {
                while (XmlRead.Read())
                {
                    if (XmlRead.NodeType == XmlNodeType.Element)
                        elementName = XmlRead.Name;
                    else
                    {
                        if ((XmlRead.NodeType == XmlNodeType.Text) &&
                            (XmlRead.HasValue))
                        {
                            switch (elementName)
                            {
                                case "version":
                                    newVersion = new Version(XmlRead.Value);
                                    break;
                                case "url":
                                    url = XmlRead.Value;
                                    break;
                                case "newfeatures":
                                    newfeatures = XmlRead.Value;
                                    break;
                            }
                        }
                    }
                }
            }
        }
        catch (Exception)
        {
            MessageBox.Show("Could not connect to update checking server.");
        }
        finally
        {
            if (XmlRead != null) XmlRead.Close();
        }
        Version curVersion = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
        if (curVersion.CompareTo(newVersion) < 0)
        {
            string title = "New Version Online";
            string question = "Download new version? \nmyProgram Version: " + newVersion.ToString();
            if (DialogResult.Yes ==
             MessageBox.Show(this, question + "\n\n" + newfeatures, title,
                             MessageBoxButtons.YesNo,
                             MessageBoxIcon.Question))
            {
                System.Diagnostics.Process.Start(url);
            }
        }  
    }

我对cocoa还很陌生,大部分的C代码都是一个片段,所以任何建议或帮助都会很好。