winform资源文件为xml如何读取?

<?xml version="1.0" encoding="utf-8" ?>
<users>
<user username="doc"/>
<user username="doc2"/>
<user username="doc3"/>
</users>

try
{
ResourceManager rm = Properties.Resources.ResourceManager;

string xmld = rm.GetObject("users").ToString();
XmlDocument xmldocument = new XmlDocument();
xmldocument.LoadXml(xmld);  //string 转xml

MessageBox.Show(xmldocument.SelectSingleNode("/users").FirstChild.Attributes["username"].Value);
}
catch (Exception e)
{
MessageBox.Show(e.ToString());
}