string resourceName = "CSharp.BLL" + ".aa.xml";
//获取当前运行的组件的嵌入式资源
//Assembly _assembly = Assembly.GetExecutingAssembly();
//引用的dll资源
Assembly _assembly = Assembly.Load("CSharp.BLL");
Stream stream = _assembly.GetManifestResourceStream(resourceName);
if(stream!=null)
{
XmlDocument xmlDoc = null;
xmlDoc = new XmlDocument();
xmlDoc.Load(stream);
}