QtPlugin compile issue

**croland** · 25th May 2007, 16:26

Hello everyone,

I am trying to create a plugin that either sets up a widget with controls or returns a QWigdet that will become a child widget of a parent. Bascially I am trying to use QtPlugin to create a MDI app and each plugin will provide a different view.

I am using Qt 4.2.2 Windows Open Source with MinGW as the compiler.

The issue I am running into is I keep getting the following error when trying to compile my test plugin:

moc_myplugin.cpp: undefined reference to 'vtable for MyPluginInterface'

When I take out the setupWidget function everthing works fine and I can even call the gethello function from a test app from the compiled plugin dll.

Thank you in advance for any help

.

- Chris

Here is the code for my plugin and interface:

//-----------------------------------
// interface.h
//-----------------------------------

#ifndef INTERFACES_H
#define INTERFACES_H

class QString;
class QWidget;

class MyPluginInterface
{
public:
virtual ~MyPluginInterface() {}
virtual QString gethello() const = 0;
virtual void createWidget(QWidget *parent = 0);
};

Q_DECLARE_INTERFACE(MyPluginInterface, "com.MyPluginInterface/1.0")

#endif //INTERFACES_H

//-----------------------------------
// myplugin.h
//-----------------------------------

#ifndef MYPLUGIN_H
#define MYPLUGIN_H

#include <QObject>
#include <QString>
#include <QWidget>
#include <QPushButton>
#include <QtGui>

#include "interfaces.h"

class MyPlugin : public QObject, public MyPluginInterface
{
Q_OBJECT
Q_INTERFACES(MyPluginInterface)

public:
// MyPluginInterface
MyPlugin(){};
~MyPlugin(){};
QString gethello() const;
void createWidget(QWidget *parent);
};

#endif //MYPLUGIN_H

//-----------------------------------
// myplugin.cpp
//-----------------------------------

#include "myplugin.h"

QString MyPlugin::gethello() const
{
return "Hello World!";
}

void MyPlugin::createWidget(QWidget *parent)
{

}
Q_EXPORT_PLUGIN2(myplugin, MyPlugin)