undefined reference to vtable

[mastupristi]

I use wxDev-Cpp beta 6.8 (with mingw 3.4 and wxwidgets 2.6.1)
I have defined a derived Class of wxComboBox, and I obtain a linker error:

undefined reference to `vtable for MyComboBox'

How can avoid this problem?

thanks

[lowjoel]

if you called DECLARE_EVENT_TABLE() in MyComboBox, make sure you defined an event table for MyComboBox

[Jorg]

It helps by showing some (stripped down) code. Remember, even pragma's can cause this. Are you using the #pragma implementation part by any chance?

- Jorgen

[mastupristi]

if you called DECLARE_EVENT_TABLE() in MyComboBox, make sure you defined an event table for MyComboBox

Here is my header file:

Code: Select all

#ifndef MYCOMBOBOX_H
#define MYCOMBOBOX_H

#include <wx/combobox.h> // inheriting class's header file

/*
 * No description
 */
class MyComboBox : public wxComboBox
{
	public:
		// class constructor
        MyComboBox(wxWindow* parent, wxWindowID id, 
               const wxString& value, 
               const wxPoint& pos, 
               const wxSize& size, 
               const wxArrayString& choices = NULL, 
               long style = 0, 
               const wxValidator& validator = wxDefaultValidator, 
               const wxString& name = wxComboBoxNameStr)
        : wxComboBox(parent, id, value, pos, size, choices, style,
                     validator, name) { };

		// class destructor
		~MyComboBox();
protected:
    void OnFocusGot(wxFocusEvent& event);
private:
    DECLARE_EVENT_TABLE();
};

#endif // MYCOMBOBOX_H

and the cpp:

Code: Select all

#include "mycombobox.h" // class's header file

BEGIN_EVENT_TABLE(MyComboBox, wxComboBox)
    EVT_SET_FOCUS(MyComboBox::OnFocusGot)
END_EVENT_TABLE()

void MyComboBox::OnFocusGot(wxFocusEvent& event)
{
	// insert your code here
}

and I use this command to link:

Code: Select all

g++.exe vsendppDlg.o vsendppApp.o mycombobox.o vsendpp_private.res -o "vsendpp.exe" -L"C:/Dev-Cpp/lib" -mwindows -lwxmsw26 -lwxmsw26_gl -lwxtiff -lwxjpeg -lwxpng -lwxzlib -lwxregex -lwxexpat -lkernel32 -luser32 -lgdi32 -lcomdlg32 -lwinspool -lwinmm -lshell32 -lcomctl32 -lole32 -loleaut32 -luuid -lrpcrt4 -ladvapi32 -lwsock32 -lodbc32 -lopengl32  

Is that correct? Have I defined correctly the event table?

thanks

[mastupristi]

It helps by showing some (stripped down) code. Remember, even pragma's can cause this. Are you using the #pragma implementation part by any chance?

I don't think (if wxDev-Cpp hasn't add it).

thanks

[waterj]

It helps by showing some (stripped down) code. Remember, even pragma's can cause this. Are you using the #pragma implementation part by any chance?

I don't think (if wxDev-Cpp hasn't add it).

thanks

I think your'd better check for something like "#pragma interface" in your code.

[DavidHart]

Maybe you just didn't post the code, but the destructor is declared but not defined. If so, that would give the error message.

If that's not it, 2 other suggestions. Remove the unnecessary semi-colons after the constructor and after DECLARE_EVENT_TABLE(). This doesn't cause the error for me using linux, but maybe in your setup . . . . .

Failing that, remove everything . Try just class MyComboBox : public wxComboBox{}; If that still fails, you'll know it's not your code. If it works, add things back one by one until the error recurs.

HTH,

David

[jazz]

Maybe you just didn't post the code, but the destructor is declared but not defined. If so, that would give the error message.

That'd be it. I get that compile error all the time cause I declare a destructor out of habit but then forget to define it if I don't need it.