hellou it's me again ;-)

i want to count number of lines in all solution textdocs (*.cs) (how to
check if doc is a Code file?)

...
applicationObject = (_DTE)application;//works fine
...
private int GetLinesNum() {
 int lines = 0;
 foreach (Project project in applicationObject.Solution.Projects) {
   foreach (ProjectItem projectitem in project.ProjectItems) {
     Document document = projectitem.Document;//not working!!
     if (document != null) {
       TextDocument textdoc = (TextDocument)document.Object("TextDocument");
       if (textdoc != null) {
         string name = document.FullName;
         name = name.ToLower();
         if (name.EndsWith(".cs")) {
           TextPoint end = textdoc.EndPoint;
            lines += end.Line;//can be done better??
         }
      }
    }
 }
 return lines;
}

and i always get null in document, even for Form1.cs which i can edit
what's wrong with this code?
when i do the same with
foreach (Document document in applicationObject.Documents) {
 TextDocument textdoc = (TextDocument)document.Object("TextDocument");
 ...
}
it works fine but all docs must be opened! i prefer the first way ;)
thx for help
//SNAKE