QAxObject Class

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# QAxObject Class Reference
[QAxContainer module]

The QAxObject class provides a QObject that wraps a COM object. More...

This class is part of the Qt ActiveQt Extension.

`#include <qaxobject.h>`

Inherits QObject and QAxBase.

Inherited by QAxScriptEngine.

List of all member functions.

## Public Members

- QAxObject ( QObject * parent = 0, const char * name = 0 )
- QAxObject ( const QString & c, QObject * parent = 0, const char * name = 0 )
- QAxObject ( IUnknown * iface, QObject * parent = 0, const char * name = 0 )
- ~QAxObject ()

## Important Inherited Members

- QVariant dynamicCall ( const QCString & function, const QVariant & var1 = QVariant ( ), const QVariant & var2 = QVariant ( ), const QVariant & var3 = QVariant ( ), const QVariant & var4 = QVariant ( ), const QVariant & var5 = QVariant ( ), const QVariant & var6 = QVariant ( ), const QVariant & var7 = QVariant ( ), const QVariant & var8 = QVariant ( ) )
- QVariant dynamicCall ( const QCString & function, QValueList<QVariant> & vars )
- QAxObject * querySubObject ( const QCString & name, const QVariant & var1 = QVariant ( ), const QVariant & var2 = QVariant ( ), const QVariant & var3 = QVariant ( ), const QVariant & var4 = QVariant ( ), const QVariant & var5 = QVariant ( ), const QVariant & var6 = QVariant ( ), const QVariant & var7 = QVariant ( ), const QVariant & var8 = QVariant ( ) )

## Detailed Description

This class is defined in the Qt ActiveQt Extension, which can be found in the `qt/extensions` directory. It is not included in the main Qt API.

The QAxObject class provides a QObject that wraps a COM object.

A QAxObject can be instantiated as an empty object, with the name of the COM object it should wrap, or with a pointer to the IUnknown that represents an existing COM object. If the COM object implements the IDispatch interface, the properties, methods and events of that object become available as Qt properties, slots and signals. The base class, QAxBase, provides an API to access the COM object directly through the IUnknown pointer.

QAxObject is a QObject and can be used as such, e.g. it can be organized in an object hierarchy, receive events and connect to signals and slots.

Warning: You can subclass QAxObject, but you cannot use the Q_OBJECT macro in the subclass (the generated moc-file will not compile), so you cannot add further signals, slots or properties. This limitation is due to the metaobject information generated in runtime. To work around this problem, aggregate the QAxObject as a member of the QObject subclass.

## Member Function Documentation

### QAxObject::QAxObject ( QObject * parent = 0, const char * name = 0 )

Creates an empty COM object and propagates parent and name to the QObject constructor. To initialize the object, call setControl.

### QAxObject::QAxObject ( const QString & c, QObject * parent = 0, const char * name = 0 )

Creates a QAxObject that wraps the COM object c. parent and name are propagated to the QWidget contructor.

See also control.

### QAxObject::QAxObject ( IUnknown * iface, QObject * parent = 0, const char * name = 0 )

Creates a QAxObject that wraps the COM object referenced by iface. parent and name are propagated to the QObject contructor.

### QAxObject::~QAxObject ()

Releases the COM object and destroys the QAxObject, cleaning up all allocated resources.

### QVariant QAxBase::dynamicCall ( const QCString & function, const QVariant & var1 = QVariant ( ), const QVariant & var2 = QVariant ( ), const QVariant & var3 = QVariant ( ), const QVariant & var4 = QVariant ( ), const QVariant & var5 = QVariant ( ), const QVariant & var6 = QVariant ( ), const QVariant & var7 = QVariant ( ), const QVariant & var8 = QVariant ( ) )

Calls the COM object's method function, passing the parameters var1, var1, var2, var3, var4, var5, var6, var7 and var8, and returns the value returned by the method, or an invalid QVariant if the method does not return a value or when the function call failed.

If function is a method of the object the string must be provided as the full prototype, for example as it would be written in a QObject::connect() call.

        activeX->dynamicCall( "Navigate(const QString&)", "www.trolltech.com" );

Alternatively a function can be called passing the parameters embedded in the string, e.g. above function can also be invoked using

        activeX->dynamicCall("Navigate(\"www.trolltech.com\");

All parameters are passed as strings; it depends on the control whether they are interpreted correctly, and is slower than using the prototype with correctly typed parameters.

If function is a property the string has to be the name of the property. The property setter is called when var1 is a valid QVariant, otherwise the getter is called.

        activeX->dynamicCall( "Value", 5 );
        QString text = activeX->dynamicCall( "Text" ).toString();

Note that it is faster to get and set properties using QObject::property() and QObject::setProperty().

It is only possible to call functions through dynamicCall() that have parameters or return values of datatypes supported by QVariant. See the QAxBase class documentation for a list of supported and unsupported datatypes. If you want to call functions that have unsupported datatypes in the parameter list, use queryInterface() to retrieve the appropriate COM interface, and use the function directly.

        IWebBrowser2 *webBrowser = 0;
        activeX->queryInterface( IID_IWebBrowser2, (void**)&webBrowser );
        if ( webBrowser ) {
            webBrowser->Navigate2( pvarURL );
            webBrowser->Release();
        }

This is also more efficient.

Example: qutlook/centralwidget.cpp.

### QVariant QAxBase::dynamicCall ( const QCString & function, QValueList<QVariant> & vars )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Calls the COM object's method function, passing the parameters in vars, and returns the value returned by the method. If the method does not return a value or when the function call failed this function returns an invalid QVariant object.

The QVariant objects in vars are updated when the method has out-parameters.

### QAxObject * QAxBase::querySubObject ( const QCString & name, const QVariant & var1 = QVariant ( ), const QVariant & var2 = QVariant ( ), const QVariant & var3 = QVariant ( ), const QVariant & var4 = QVariant ( ), const QVariant & var5 = QVariant ( ), const QVariant & var6 = QVariant ( ), const QVariant & var7 = QVariant ( ), const QVariant & var8 = QVariant ( ) )

Returns a pointer to a QAxObject wrapping the COM object provided by the method or property name, passing passing the parameters var1, var1, var2, var3, var4, var5, var6, var7 and var8.

If name is provided by a method the string must include the full function prototype.

If name is a property the string must be the name of the property, and var1, ... var8 are ignored.

The returned QAxObject is a child of this object (which is either of type QAxObject or QAxWidget), and is deleted when this object is deleted. It is however safe to delete the returned object yourself, and you should do so when you iterate over lists of subobjects.

COM enabled applications usually have an object model publishing certain elements of the application as dispatch interfaces. Use this method to navigate the hierarchy of the object model, e.g.

        QAxWidget outlook( "Outlook.Application" );
        QAxObject *session = outlook.querySubObject( "Session" );
        if ( session ) {
            QAxObject *defFolder = session->querySubObject(
                                    "GetDefaultFolder(OlDefaultFolders)",
                                    "olFolderContacts" );
            //...
        }

Example: qutlook/centralwidget.cpp.

This file is part of the Qt toolkit. Copyright © 1995-2004 Trolltech. All Rights Reserved.