Qt 插件:无法从 Qt 插件获取枚举的元数据
Qt plugin: Unable to get enum's metadata from a Qt plugin
我可以从我的 Qt 插件访问很多元数据,但我无法访问枚举作为 QMetaEnums。但是,我能够在我的 class returns 枚举中获取该方法,并且能够将其转换为 QMetaType 并获取其 ID (1026)。我也需要 QMetaEnum 中包含的信息。我想我错过了什么。请看看我的代码:
//Plugin interface
class PluginInterface
{
public:
virtual void initialize() = 0;
};
#define PluginInterface_iid "pluginInterface"
Q_DECLARE_INTERFACE(PluginInterface, PluginInterface_iid)
//Actual plugin implementing PluginInterface
enum Fruit{ Apple, Pear, Mango };
Q_DECLARE_METATYPE(Fruit)
class MYQTCALCPLUGINSHARED_EXPORT MyQtCalcPlugin : public QObject, PluginInterface
{
Q_CLASSINFO("version", "0.1")
Q_OBJECT
Q_PLUGIN_METADATA(IID PluginInterface_iid FILE "myqtcalcplug.json")
Q_INTERFACES(PluginInterface)
Q_ENUMS(Fruit)
public:
explicit MyQtCalcPlugin(QObject *parent = 0);
void MyQtCalcPlugin::initialize()
{
qRegisterMetaType<MyQtCalcPlugin*>("MyQtCalcPluginPtr");
qRegisterMetaType<Fruit>("Fruit");
qRegisterMetaType<Fruit*>("FruitPtr");
}
public slots:
Fruit TasteFruit()
{
return Fruit::Apple;
}
};
#endif // MYQTCALCPLUGIN_H
//application that is reading the metadata
QPluginLoader pluginLoader(pluginPath);
if (pluginLoader.load());
QObject *pluginInstance = pluginLoader.instance();
auto pluginInterface = qobject_cast<PluginInterface*>(pluginInstance);
pluginInterface->initialize();
const QMetaObject *pMetaObject = pluginInstance->metaObject();
int count = pMetaObject->enumeratorCount(); //count becomes 0
Enum 已从 class 外部移动到其内部。这解决了这个问题。 Q_DECLARE_META_TYPE(Fruit) 和 qRegisterMetaType 是多余的:
#define PluginInterface_iid "pluginInterface"
Q_DECLARE_INTERFACE(PluginInterface, PluginInterface_iid)
//Actual plugin implementing PluginInterface
class MYQTCALCPLUGINSHARED_EXPORT MyQtCalcPlugin : public QObject, PluginInterface
{
Q_CLASSINFO("version", "0.1")
Q_OBJECT
Q_PLUGIN_METADATA(IID PluginInterface_iid FILE "myqtcalcplug.json")
Q_INTERFACES(PluginInterface)
Q_ENUMS(Fruit)
public:
enum Fruit
{
Apple,
Pear,
Mango
};
}
我可以从我的 Qt 插件访问很多元数据,但我无法访问枚举作为 QMetaEnums。但是,我能够在我的 class returns 枚举中获取该方法,并且能够将其转换为 QMetaType 并获取其 ID (1026)。我也需要 QMetaEnum 中包含的信息。我想我错过了什么。请看看我的代码:
//Plugin interface
class PluginInterface
{
public:
virtual void initialize() = 0;
};
#define PluginInterface_iid "pluginInterface"
Q_DECLARE_INTERFACE(PluginInterface, PluginInterface_iid)
//Actual plugin implementing PluginInterface
enum Fruit{ Apple, Pear, Mango };
Q_DECLARE_METATYPE(Fruit)
class MYQTCALCPLUGINSHARED_EXPORT MyQtCalcPlugin : public QObject, PluginInterface
{
Q_CLASSINFO("version", "0.1")
Q_OBJECT
Q_PLUGIN_METADATA(IID PluginInterface_iid FILE "myqtcalcplug.json")
Q_INTERFACES(PluginInterface)
Q_ENUMS(Fruit)
public:
explicit MyQtCalcPlugin(QObject *parent = 0);
void MyQtCalcPlugin::initialize()
{
qRegisterMetaType<MyQtCalcPlugin*>("MyQtCalcPluginPtr");
qRegisterMetaType<Fruit>("Fruit");
qRegisterMetaType<Fruit*>("FruitPtr");
}
public slots:
Fruit TasteFruit()
{
return Fruit::Apple;
}
};
#endif // MYQTCALCPLUGIN_H
//application that is reading the metadata
QPluginLoader pluginLoader(pluginPath);
if (pluginLoader.load());
QObject *pluginInstance = pluginLoader.instance();
auto pluginInterface = qobject_cast<PluginInterface*>(pluginInstance);
pluginInterface->initialize();
const QMetaObject *pMetaObject = pluginInstance->metaObject();
int count = pMetaObject->enumeratorCount(); //count becomes 0
Enum 已从 class 外部移动到其内部。这解决了这个问题。 Q_DECLARE_META_TYPE(Fruit) 和 qRegisterMetaType 是多余的:
#define PluginInterface_iid "pluginInterface"
Q_DECLARE_INTERFACE(PluginInterface, PluginInterface_iid)
//Actual plugin implementing PluginInterface
class MYQTCALCPLUGINSHARED_EXPORT MyQtCalcPlugin : public QObject, PluginInterface
{
Q_CLASSINFO("version", "0.1")
Q_OBJECT
Q_PLUGIN_METADATA(IID PluginInterface_iid FILE "myqtcalcplug.json")
Q_INTERFACES(PluginInterface)
Q_ENUMS(Fruit)
public:
enum Fruit
{
Apple,
Pear,
Mango
};
}