CreateMainMenu();
ClearMainMenu();

CreateOptionsMenu();
ClearOptionsMenu();

this

class MainMenu : public wxFrame{
// ctor Create Controls with this as parameter for the parentwinows
//.....
};

void OnButton1(){

// Here I want create an object from the Menu2, but this doesn?t go.
// My problem ist, that I don?t know what I can give as parent.
// I don?t know the name of the window, I?ve create in the MainMenu Ctor
Menu2 *m = new Menu2(this); // this don?t work! (programm crashed)

}

class Menu2 : public wxFrame{
// in the ctor I create the Controls 
Menu2(wxWindow *parent){
wxButton *b = new wxButton(parent);
// ....
}

Need every class an own eventtable?
Must be every class I use in an eventtable derrivied from wxApp?

Why would you create a class that should be a menu, like MainMenu, and derive it from wxFrame instead of wxMenu?

Seriously: Have you worked with C++, Java or any other object oriented programming language before?

No, it doesn't have to have an eventtable. If you need one, declare it, otherwise don't. Events generated by derived classes which are not dealt with in the class itself will nornmally propagate to it's parent.

class mainmenu : public wxFrame{
    // ctor create the Window, but I don?t 
    MainMenu(const wxString& title, const wxPoint& pos, const wxSize& size)
    : wxFrame(frame, -1, title, pos, size)
    {
    // Create Controls
    } 
    // The variable for the window:
    wxFrame *frame; 
    // here I delete the controls (I want this methode, not a dtor):
    ClearMenu(){
    // deleteControls
    } 
    // Methode will be called if the Menu2 Button was pressed:
    void OnMenu2Button(); 
};

class Menu2 : public wxFrame{
    // The ctor
    Menu2(wxWindow *parent){
    // Here I create Controls in the window, that the mainmenu have created:
    wxButton *b = new wxButton(parent,-1);
              b->Show(TRUE);
    } 
    // here I delete the controls (I want this methode, not a dtor):
    ClearMenu(){
    // deleteControls
    delete b;
    }   
};

void MainMenu::OnButton2(){
// Here I clear the mainmenu
ClearMenu();
// And I want to create an instance of Menu2:
Menu2 *m = new Menu2(frame); // Programm crashed by creating Menu2!
}

class mainmenu : public wxFrame{
    MainMenu(const wxString& title, const wxPoint& pos, const wxSize& size)
    : wxFrame(frame, -1, title, pos, size)
    {
    // Create Controls
    } 
    // The variable for the window:
    wxFrame *frame; 
    // here I delete the controls (I want this methode, not a dtor):
    ClearMenu(){
    // deleteControls
    } 
    // Methode will be called if the Menu2 Button was pressed:
    void OnMenu2Button(); 
};

Because I?ve thinked that every class, that I want to use in an Eventtable must be derrivied from wxFrame and I don?t know wxMenu.

Yes I?ve and I?ve much more C++ experience as you seem to think.