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im a com beginner, i know its more complex than normal usage. Here i list some classes as following:
class A{
//...some member variables, such as c strings, and other class variables
};
class B{
//...some member variables, such as c strings, and other class variables
};
class C{
//...some member variables, such as c strings, and other class variables
A* m_pAobjects;
B* m_pBobjects;
};
In the project, there would be only one instance of class C, but there would be more than one B instances and A instance; And i can create one C instance, which will read some data from some files or generate some data on the fly; and i can get the count of its internal A or B instances, retrieve specified objects from the instances.
But, i don't know how to design the project to com architecture. My main problem is,how to design and implement the interfaces? and how to transfer the parameters between the com client and the server?
thanks
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As a start: Find something on Unified Modelling Language (UML) related to COM, though be careful as some UML descriptions can get a bit complicated. Basically get some paper, draw your COM objects as boxes and any interface such as IUnknown or IMySettings as, well, 'lollipop' or spoon shapes on those boxes. Find a few examples and you'l see what I mean.
Then try a sequence diagram to show the messages (calls) between the COM objects. Once you're satisfied you have the messages sorted you need to design interfaces to provide methods which convey those messages.
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im agree with you. Although i know little about uml, im puzzled by this condition. But it can be designed in plain C++ easily. About COM, at this condition, class C can be implements as interface C is easy, but how to retrieve its internal instances B or A? No matter C delegate A and B or C contain B and C, there would be more than one interfaces be created......
i think i have not understand the between COM interface and COM object.
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thanks for you advise. After i read the implement about ADO database, i know how to designed such com interfaces for such condition.
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As you mention, you can't really consider designing how to implement COM objects in, say, C++ until you are up to speed with COM Objects and Interfaces and have some idea of how they can be used.
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yes. im just a newbie for com. But the question is upgrading, although i had learnt how to implement it from ADO. Here, class A has B type member pointer, but B is a union type, which can point to a A object or anther different object:
class A{
//some other members
struct B* m_pB;
};
struct B{
int type;//indicate the type of next field
union{
char* szText;
class A* pA;
}data;
};
if i translate it to interface, that, i can get IB from IA, but if IB instance's data field point to any IA object, how should i get the IA object? if i get IA object as normal, the previous IA object,the owner of IB, would lost its attributes! right?
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Your Inside COM should tell you most of this. Again concentrate on COM objects and Interfaces or some examples and you will realise how to phrase 'IB instance's data field' in COM terms.
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I really have that book, and i had read it twice, in fact.
I will study harder to do that work.
Thank you.
Regards.
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hello all,
i want to customize the context menu which appears when one clicks
on to a mail-id(in front of From: or To .
while browsing for it, i found that there are 2 ways of doing this via xml or via dll's.
i have chosen to write a dll for it as it offers much more flexibility,but the real problem is using what i should write a dll .NET(vb,c# etc) or using unmanaged code(vc++). & what are the problems that could arise by using unmanaged code.
you can reply me at: n.chudekar.31@gmail.com
hoping for your kind co-operation.
thanks n regards,
nikhil.
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Hi,
I succeeded using COM objects from my Java program using the Java Callable Wrappers (JCW)
I used Microsoft JVM and Microsoft JDK to implement JCW.
Will the same run on SUN Java VM as well under Microsoft Windows Platforms?
If not, then how can I use COM objects from java programs that runs on SUN Java VM under Microsoft Windows Platforms?
Thanks in advance
cheers
Varghese Paul
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hello every one
I make an ActiveX using Flash.ocx, i didn't create a window for Flash control, just use windowless object(IOleInPlaceObjectWindowless).
and i use OleDraw() to draw the Flash content to my HDC:
OleDraw(pFlashViewObject, DVASPECT_TRANSPARENT, hDC, &rc);
Everything is good in the "ActiveX Control Test Container", the Flash content is drawn.
but when i use my ActiveX in Internet Explorer, the OleDraw() draw nothing!
the HRESULT is ok, but hDC is just white(i save it to a BMP file)! 
I test my ActiveX on some other browers(support ActiveX), they work fine too!
only IE has this problem! IE don't like an ActiveX(mine) OleDraw another ActiveX(Flash.ocx)??
Is it a security problem of Internet Explorer? (i mean: IE prevent calling OleDraw or something else from my ActiveX to Flash.ocx??)
i want to draw Flash content to my ActiveX's HDC, and use it on IE browser, is there any solution??
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I have an activex control, written using MFC that is embedded on a web page with the Object tag and the following properties:
PARAM NAME="_Version" VALUE="458752"
PARAM NAME="_ExtentX" VALUE="9843"
PARAM NAME="_ExtentY" VALUE="7373"
PARAM NAME="_StockProps" VALUE="1"
Can anyone give me some detail as to what each property means (links to some documentation would be great also). I have seen these properties on a number of controls on the web.
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Hello All,
I have written a small plug-in in Eudora. This plug-in adds two menu-item in the Tool menu also on toolbar. I have also handle there events using EMS-API. But in that event i want header part of currently selected mail.
How can i get Header information in ems_special_hook function?
Hoping for your kind co-operation.
Thanks
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anyone knows solution of this error......
Error HRESULT E_FAIL has been returned from a call to a COM component.
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Well, you know the question is a bit vague...
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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OIOIC is a completely new object-oriented mechanism for the C programming language.
Please download the "OIOIC-Primer-2nd-Edition-English.tar.gz". (the English version of << OIOIC Primer >> )
http://code.google.com/p/oioic/downloads/list
Welcome your advice!
Using OIOIC, you can describe the flower, birds, grass, insects, trees, houses ...
Using OIOIC, you can describe the elements, atoms, protons, electrons ...
Using OIOIC, you can describe the earth, the sun, the Milky Way galaxy, collapsar ...
Using OIOIC, you can describe ...
1. OIOIC perfectly supplies the gap of object-oriented technology for the C programming language;
2. OIOIC perfectly solved the multiple inheritance problem in the Software World;
3. OIOIC perfectly objectivizes multithreading access control of object;
4. OIOIC unifies the norm of components in the Software World;
5. OIOIC unifies the structure of code tree in the Software World;
6. OIOIC unifies the thinking of object-oriented programming in the Software World;
7. OIOIC unifies all advanced programming languages in the Software World, to make the C programming language as the preferred.
modified on Wednesday, March 11, 2009 9:54 PM
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I have packed the English version individually.
Please download the "OIOIC-Primer-2nd-Edition-English.tar.gz". (the English version of << OIOIC Primer >> )
http://code.google.com/p/oioic/downloads/list
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As a beginner I have a question for those of you who know far more than I do. My built in infrared device on a Compaq 98SE platform gives an initialization error 45, which I think is not a driver issue.
This infrared device is on LPT3 and COM4. However, ‘mode com4’ in DOS returns an illegal device message AND under debug- COM4 has a value of 00 00. The com address actually used by the Infrared device (3E8) is shown under COM3 instead of COM4 !! COM3 also returns an illegal device message with the mode com3 command. Does this explain my Infrared initialization error?
Thanks
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Hi,
This is COM as in Component Object Model rather than COMmunication port, but I mistakenly bought 'Inside COM' (Dale Rogerson) when working on ports and then a few months later got a job that lasted 10 years 'cos I new all about COM!
Anyway, there is various stuff on the net such as this [^] saying BIOS does'nt recognise COM3 and 4.
DOS often has a problem with COM3 and COM4, again there's lots on the net. I think its usually assumed that the Operating System e.g. Windows will handle 3 and 4 etc OK so it doesn't matter at the BIOS level.
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All 4 COM ports are listed in win.ini with default settings shown. I know from other Freeware diagnostic programs that COM1-4 exist. COM4 is probably virtual, because it does have 00 00 value in debug and is not recognized by the mode command. But in Modems Properties -> Diagnostics, COM4 displays as having no address or settings, all blank. COM2 is used by the modem, which works. My Compaq bios settings only allow me to enable and disable ports. No other options.
The main main clue is that COM3 shows the address for the Infrared Device, and this port does not open. Whereas the Infrared Device is seeking and using COM4, and I get an initialization error when opening IR on my computer.
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Sorry I can't help. All I can suggest is perhaps post your problem on the Code Project Hardware & Devices forum.
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Please anyone help me where am doing wrong.
Dim AcadApp As AutoCAD.AcadApplication
Set AcadApp = CreateObject("AutoCAD.Application")
when i am executing the above code it i working fine.
Dim tempLine As AutoCAD.AcadLine
Set tempLine = CreateObject("AutoCAD.AcadLine")
when executing this one, i am getting "ActiveX component can't create object"
Thanks in advance
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You probably have to create a drawing in your application, say, AcadApp.NewDrawing() (just guessing here, though it may be a model then a drawing) then in your created Drawing do Drawing.AddLine(pt1, pt2)
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Hi,
Are you sure the AutoCAD.AcadLine is COM object? You can check in Registry if you not able to find any where else and look for this ProgID.
-
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