The OpenGL example demonstrates the use of the default factory and QAxFactory::isServer (), and the implementation of an additional COM interface using QAxBindable and QAxAggregated . The server executable can run both as an ActiveX server and as a stand-alone application.
The ActiveX control in this example uses the QGlWidget class in Qt to render an OpenGL scene in an ActiveX. The control exposes a few methods to change the scene.
The application uses
QAxFactory
through the
QAXFACTORY_BEGIN()
,
QAXCLASS()
and
QAXFACTORY_END()
macros to expose the
GLBox
widget as an ActiveX control.
#include <QAxFactory> QAXFACTORY_BEGIN( "{2c3c183a-eeda-41a4-896e-3d9c12c3577d}", // type library ID "{83e16271-6480-45d5-aaf1-3f40b7661ae4}") // application ID QAXCLASS(GLBox) QAXFACTORY_END()
The implementation of
main
initializes the
QApplication
object, and uses
QAxFactory::isServer()
to determine whether or not it is appropriate to create and show the application interface.
/* The main program is here. */ int main(int argc, char *argv[]) { QApplication a(argc,argv); if (QOpenGLContext::openGLModuleType() != QOpenGLContext::LibGL) { qWarning("This system does not support OpenGL. Exiting."); return -1; } if (!QAxFactory::isServer()) { GLObjectWindow w; w.resize(400, 350); w.show(); return a.exec(); } return a.exec(); }
GLBox
class inherits from both the
QOpenGLWidget
class to be able to render OpenGL, and from
QAxBindable
.
#include <QAxBindable> class GLBox : public QOpenGLWidget, public QOpenGLFunctions_1_1, public QAxBindable { Q_OBJECT Q_CLASSINFO("ClassID", "{5fd9c22e-ed45-43fa-ba13-1530bb6b03e0}") Q_CLASSINFO("InterfaceID", "{33b051af-bb25-47cf-a390-5cfd2987d26a}") Q_CLASSINFO("EventsID", "{8c996c29-eafa-46ac-a6f9-901951e765b5}")
类重实现 QAxBindable::createAggregate () 函数从 QAxBindable 以返回指针指向 QAxAggregated 对象。
public: explicit GLBox(QWidget *parent, const char *name = nullptr); virtual ~GLBox(); QAxAggregated *createAggregate() override; public slots: void setXRotation(int degrees);
The implementation file of the
GLBox
类包括
objsafe.h
system header, in which the
IObjectSafety
COM interface is defined.
#include <objsafe.h>
类
ObjectSafetyImpl
is declared using multiple inheritance to subclass the
QAxAggregated
class, and to implement the IObjectSafety interface.
class ObjectSafetyImpl : public QAxAggregated, public IObjectSafety { public:
The class declares a default constructor, and implements the queryInterface function to support the IObjectSafety interface.
explicit ObjectSafetyImpl() = default; long queryInterface(const QUuid &iid, void **iface) override { *iface = nullptr; if (iid != IID_IObjectSafety) return E_NOINTERFACE; *iface = static_cast<IObjectSafety*>(this); AddRef(); return S_OK; }
Since every COM interface inherits
IUnknown
QAXAGG_IUNKNOWN
macro is used to provide the default implementation of the
IUnknown
interface. The macro is defined to delegate all calls to
QueryInterface
,
AddRef
and
Release
to the interface returned by the controllingUnknown() function.
QAXAGG_IUNKNOWN;
The implementation of the
IObjectSafety
interface provides the caller with information about supported and enabled safety options, and returns
S_OK
for all calls to indicate that the ActiveX control is safe.
HRESULT WINAPI GetInterfaceSafetyOptions(REFIID riid, DWORD *pdwSupportedOptions, DWORD *pdwEnabledOptions) override { Q_UNUSED(riid); *pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA | INTERFACESAFE_FOR_UNTRUSTED_CALLER; *pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA | INTERFACESAFE_FOR_UNTRUSTED_CALLER; return S_OK; } HRESULT WINAPI SetInterfaceSafetyOptions(REFIID riid, DWORD pdwSupportedOptions, DWORD pdwEnabledOptions) override { Q_UNUSED(riid); Q_UNUSED(pdwSupportedOptions); Q_UNUSED(pdwEnabledOptions); return S_OK; } };
The implementation of the
createAggregate()
function just returns a new
ObjectSafetyImpl
对象。
QAxAggregated *GLBox::createAggregate() { return new ObjectSafetyImpl(); }
要构建范例必须先构建
QAxServer
库。然后运行
qmake
和 make 工具在
examples/activeqt/wrapper
.
demonstration 要求您的 WebBrowser 支持 ActiveX 控件,并启用脚本。
In contrast to the other QAxServer examples Internet Explorer will not open a dialog box to ask the user whether or not the scripting of the GLBox control should be allowed (the exact browser behaviour depends on the security settings in the Internet Options dialog).
<SCRIPT LANGUAGE="JavaScript"> function setRot( form ) { GLBox.setXRotation( form.XEdit.value ); GLBox.setYRotation( form.YEdit.value ); GLBox.setZRotation( form.ZEdit.value ); } </SCRIPT> <p /> An OpenGL scene:<br /> <object ID="GLBox" CLASSID="CLSID:5fd9c22e-ed45-43fa-ba13-1530bb6b03e0" CODEBASE="http://qt.nokia.com/demos/openglax.cab"> [Object not available! Did you forget to build and register the server?] </object><br /> <form> Rotate the scene:<br /> X:<input type="edit" ID="XEdit" value="0" /><br /> Y:<input type="edit" name="YEdit" value="0" /><br /> Z:<input type="edit" name="ZEdit" value="0" /><br /> <input type="button" value="Set" onClick="setRot(this.form)" /> </form>