64 bit COM component

Hi everyone.I had to make a dll from my current source to use in C#.I did it with QAxfactory and Qt 4.8.6 and made a dll and used in C# but when I set target build to 64 bit in vs studio my C# program cannot start because my dll(that I have built from my qt source) was 32 bit.I compiled my qt program 64 bit and made 64 bit dll but when I want to add it as COM component(I register it with Regsvr32.exe) it gives me this error :Self registration for d:\.......dll faild.I compiled it with qt 5.2.1 and the result was the same.What should I do???

Code:

---

#ifndef OBJECTS_H
#define OBJECTS_H
 
#include <QWidget>
#include <QColor>
QT_BEGIN_NAMESPACE
class QVBoxLayout;
QT_END_NAMESPACE
class QSubWidget;
class CirclesGraphicsScene;
class CirclesGraphicsView;
//! [0]
class Circles : public QWidget
{
    Q_OBJECT
    Q_CLASSINFO("ClassID", "{d574a747-8016-46db-a07c-b2b4854ee75c}")
    Q_CLASSINFO("InterfaceID", "{4a30719d-d9c2-4659-9d16-67378209f822}")
    Q_CLASSINFO("EventsID", "{4a30719d-d9c2-4659-9d16-67378209f823}")
    Q_PROPERTY(QColor backgroundColor READ backgroundColor WRITE setBackgroundColor)
    Q_PROPERTY(int circleNumber READ circleNumber WRITE setCircleNumber)
 
    void createScene();
public:
    Circles(QWidget *parent = 0);
 
    QSize sizeHint() const;
    QColor backgroundColor()const;
    int circleNumber()const{return _n;}
 
public slots:
 
//--general
    void setBackgroundColor(QColor color);
    void setCircleNumber(int n);
 
//--axes
    void setAxesPen(QColor color, int w , int penStyle);
 
//--circles
    void addCircles(int r, int n, int s, int e);
 
........//the rest

---

When you register the COM DLL, are the 64-bit Qt DLLs used by the COM server in the PATH where regsvr32 can find them?

Also, I do not know if Qt COM DLLs need the qwindows.dll in the platforms subdirectory under the location of the COM DLL. Qt executables need this.

Thank you for your replying.I put QtCore4.dll ,QtGui4.dll and my dll(that has been created from source) together in the same directory then I register it with regsvr32 successfully but when I want to add it in visual studio as Com component(toolbox-->right click--->choose Item--->COMcomponent)it give me this error self registration for ......dll faild.

You need to have all the dependencies of the Qt libraries
http://qt-project.org/doc/qt-5/windo...cation-package

But I don not have any problem when I make 32 bit dll.I do the same things for 64 bit but it gives me this error.

Is Visual Studio a 64-bit app or a 32-bit app? Many Windows apps have not been ported to 64-bit versions. Just because Visual Studio can generate 64-bit code does not mean that Visual Studio itself is a 64-bit app. If it is a 32-bit app, it probably can't load an in-process 64-bit COM DLL. I don't think you can do anything to fix that. Unlike the change from 16-bit to 32-bit, there is no "thunking" in Windows to allow a 32-bit app to use a 64-bit DLL.

You could try building your COM component as an out-of-process server. Or move into the modern world and not use COM at all :-).

Thank you for replying.Could you tell me how can I build my Com component as an out-of-process server???