I have a main window and inside this main window, there's a menu section (my program references MaterialDesignInXamlToolKit, but I guess that doesn't matter as for my question). 

Because the program needs to be somewhat super flexibe and super extensible, the menu items are not defined via code. Each MenuItem is based on Namespace.Name of one view, stored in the database. 

To open a menuitem, there's an action which then calls a method, so the view will open in a tab item. 

`Action ac = new Action(() => Open<Xyz.Maschine.VerwaltungView>(item.Bezeichnung));`

(item.Bezeichnung refers to the name that will be displayed as header in the tab)

My problem is the Xyz.Maschine.Verwaltung. It's a fiexed reference to my view which I don't know at that point of time (plus it just seeems to be wrong to create my menu items fix). It should be filled in automatically, depending on the menu item selected. So I tried many many things, but this one seems to explain what I am trying to figure out: 

```
string strac = item.NamespacePassForm + "." + item.PassFormView;
Action ac = new Action(() => Open<strac>(item.Bezeichnung));

```

If you need more details, I'll edit the post and put some more code.