how to create a COM object - COM Discussion Boards

youyou789@google.com14-Jun-04 9:51

14-Jun-04 9:51

thanks, ian.
I am a new COM guy, but I think I can not find the answer anywhere in
1. Inside COM, MS Press
2. Inside DCOM, MS Press
3. ATL Internal, Addison-Wesley
4. Inside COM+, MS Press
5. Inside ATL, MS Press
6. COM+ Programming: A Practical Guide Using Visual C++ and ATL, Pretice

May I ask where I can find an example of this kind of usage? Thanks again. COM Guru.

Re: CoRegisterClassObject

ian mariano14-Jun-04 10:02

ian mariano

14-Jun-04 10:02

You'd basically create such an object the same way you do any normal COM object, using CoCreateInstance. There's a small simple ATL COM example on CodeGuru. Google's also a good place to start.

Ian Mariano - Bliki | Blog

"We are all wave equations in the information matrix of the universe" - me

How to connect to the running OAT instance?

oleg6314-Jun-04 4:29

oleg63

14-Jun-04 4:29

Hello,
The original program(OLE Automation server) was impemented on Borland Delphi. But the program don't register itself in ROT during start-up(ie program don't call RegisterActiveObject()).
- How can I connect to the running instance of the program?
I can get PID from processes list. Can I some how use that for inquiering the interface pointer(IDispatch)?
Thanks for any suggestions.

How can I initialize tapiFax

GuruVN13-Jun-04 19:23

GuruVN

13-Jun-04 19:23

Dear sir !
+. How can I initialize tapiFax
+. Tapi3.x which is support send/recevice Fax ?
+. Please help me

How to Create a COM object from a nominated EXE

Guy le Mar8-Jun-04 15:51

Guy le Mar

8-Jun-04 15:51

It's possible to use LoadLibrary() and GetProcAddress("DllGetClassObject") on a DLL in order to obtain a ClassFactory. You can then use the ClassFactory to create a COM object.

Is there is an equivalent technique that can be used for an EXE?
That is, can I create a COM object from a nominated instance of an EXE?

Thanks in advance.

Passing BSTR and Short variables in a function

tommcf8-Jun-04 13:52

tommcf

8-Jun-04 13:52

Hi,
I have a function that passes the following arguments:

void SignOn(BSTR* Name, BSTR* Password, BOOL* UseProxy, BSTR*
ProxyServer, short* ProxyPort);.

I declared the following variables which I pass to the function

BSTR Name = ::SysAllocString(L"coinpig");
BSTR Password = ::SysAllocString(L"aug2203");
BOOL useproxy = 0;
BSTR proxyServer = ::SysAllocString(L"0");
short ProxyPort = 0;
short * strPortptr = &ProxyPort;

When I use the active-x control test container and specify that all
values are BSTR the function works properly. When I call the function
with the variables I declared, the program exits with code 3. I am
new to MFC, and greatly appreciate any help.

Thank you,
Tom

Re: Passing BSTR and Short variables in a function

Anonymous9-Jun-04 19:40

Anonymous

9-Jun-04 19:40

How are you calling the SignOn function in your code?

To call SignOn with the variables you have created and the function prototype you have given:

<code>
SignOn(&Name, &Password, &useProxy, &proxyServer, strPortptr);

Or you could prototype your function like:

<code>
void SignOn(BSTR Name, BSTR Password, BOOL UseProxy, BSTR ProxyServer, short ProxyPort);

and then call the function:

<code>
SignOn(Name, Password, UseProxy, ProxyServer, ProxyPort)

The only difference between the two: the former uses pointers as parameters, whereas the latter does not.

I prefer the second approach unless I need to logically change the value of more than one variable in which case I would change my parameters to use pointers. Functions can only have one physical return value.

Hope this helps!

how to create a COM object

iceman117-Jun-04 17:17

iceman11

7-Jun-04 17:17

HI..i am a newbie in COM tech.

i have a class coded in VC++ which i need to create into a COM for use in my vb.net application..

i have use a ATL COM Appwizard to create a com. add a new atl object already.

i keep getting this error.

i need to pass in a parameter to the constructor of the class i created..seems like i cannot instaniate my object.

c:\program files\microsoft visual studio\vc98\atl\include\atlcom.h(1827) : error C2259: 'CComObject<class ctranscodeengine="">' : cannot instantiate abstract class due to following members:
c:\program files\microsoft visual studio\vc98\atl\include\atlcom.h(1823) : while compiling class-template member function 'long __stdcall ATL::CComCreator<class atl::ccomobject<class="" ctranscodeengine=""> >::CreateInstance(void *,const struct _G UID &,void ** )'

PLS help...

thks in advance...

iceman

Download my .ocx and 2 depending dll’s?

anderslundsgard6-Jun-04 21:02

anderslundsgard

6-Jun-04 21:02

Hi,
I’m developing an ActiveX-control in VS C++ 6.0 (WinXP): works fine.
For deployment, I’m using VS.NET for making the Cab-file (New project: Cab
Project). Adds ocx and builds Cab: works fine.

Problem: The .ocx is depending on 2 other dlls, as it is now they are downloaded and registered manually: this works some times, some times it is "Dll Hell".... "Dll hell" occurs when updating ocx and dlls.... is there any way to force registration and so on? My belive is that it will work fine if I just adds the dll to the Cab File-project, could that be right? If so, how do I do it in VS.NET (I know how to add the files, but it’s not working when adding the depending dlls)?

I’m also a bit confused of the making of the Cab File, with VS.NET (Cab Project, OSD-file) it’s easy, but I don’t know what I’m doing... old tech, with INF-file, it was harder, but more open I guess?

Which is the best solution in my case? Confused | :confused:

...and justice for all

APe

Implementing Span tag

Member 5281555-Jun-04 0:22

Member 528155

5-Jun-04 0:22

HI,
I need to implemnent span tag style(overline etc) in vc++ can anyone help me out... plz thanx....

Helping hands are greater than praying lips

lokesh

Re: Implementing Span tag

Andrew Quinn AUS6-Jun-04 22:23

Andrew Quinn AUS

6-Jun-04 22:23

Hi Lokesh,

Not too sure what you are after but here I've done an example that may be what you are looking for:

MSHTML::IHTMLDocument2Ptr spDoc(m_ctlWeb1.GetDocument());
if (spDoc)
{
    MSHTML::IHTMLDocument3Ptr spDoc3 = spDoc;
    if (spDoc3)
    {
        MSHTML::IHTMLElementPtr spElem = spDoc3->getElementById(_bstr_t("idSpan1"));
        if (spElem)
        {
            spElem->innerText = _bstr_t("Hello There");
            MSHTML::IHTMLStylePtr spElemStyle = spElem->style;
            if (spElemStyle)
            {
                spElemStyle->textDecorationOverline = true;
            }
        }
    }
}

So in the code above we look for an element called 'idSpan1', set the text, and then set the text decoration style to be Overline. Hope this is near the mark.

For further style information go to MSDN and look at the following interfaces:

IHTMLStyle
IHTMLStyle2
IHTMLStyle3
IHTMLStyle4

Hope this helps,
Andy

How to call methods of an appobject directly?

Roozbeh693-Jun-04 18:32

Roozbeh69

3-Jun-04 18:32

Hello everybody,

I am a beginner in com programming, and i have a question:
I have created an ATL 3.0 project including a simple object named MyObj with the attribute of 'appobject' on it's coclass. It has a property named MyString that holds string values. I have successfully built it and then tested it from vb. I have access to MyString property directly without instantiating MyObj. everythings is Ok.
but I have problem with VC. From a Console application which has access to that type library (via import directive) MyString property cannot be accessed without qualification. With the statement:

MyString = "Hello world!";

compiler generates following error:

error C2065: 'MyString' : undeclared identifier

what is the problem? do you think i should use a special syntax?
if so, would you please help me to know how i can use it?

thanks in advance
Roozbeh

Re: How to call methods of an appobject directly?

Andrew Quinn AUS3-Jun-04 22:15

Andrew Quinn AUS

3-Jun-04 22:15

Hi,

Not to sure why you are getting a problem.

Here is an example of how to use it in VC++ (see if it differs to yours)

First, the #import

#import "D:\My Projects\C++\MyObj\MyObj.tlb"
using namespace MyObjLib;

Add the namespace to avoid any conflicts with other COM objects you may use that will have the same name.

Now when using it:

MyObjLib::IMyObjPtr pMyObj = NULL;
try
{
    if (SUCCEEDED(pMyObj.CreateInstance(__uuidof(MyObjLib::MyObj))) && pMyObj != NULL)
    {
        pMyObj->MyString = _T("Hello");
    }
}
catch(_com_error &e)
{
}

This ultimately will use the wrapper method PutMyString( _bstr_t pVal ) that is defined in the two new files generated by the #import statement.

These should be in your Debug/Release directories and called MyObj.tlh and MyObj.tli. Ones the header file, the other the implementation file.

Have a look through them to see how your COM object has been wrapped.

Hope this has helped,
Andy

Automating Office

no_reg_name3-Jun-04 6:14

no_reg_name

3-Jun-04 6:14

I'm trying to automate PowerPoint from an MFC application. When I import office TypeLib (from Add MFC Class from Typelib), VS generates these wrappers for the COM calls.

How would one find out what different classes and methods do? Certainly wrappers are not documented in MSDN, and I don't know how to get to the actual COM interfaces being used.

btw I'm using VS.NET 2003 and Office 2003

Re: Automating Office

sas22223-Jun-04 9:27

sas2222

3-Jun-04 9:27

You can use the "OLE/COM Object Viewer" accessible
from the Studio .net Tools menu.

open up the tool from the "Tools | OLE/COM Object Viewer" menu
selection and browse to the Microsoft Powerpoint x.xObject Library
in the left hand tree view. the right hand pane should fill up with
registration information. doiuble click in the left hand treeview
on the power point text and it will open the type library definition
(methods, etc..) for the ppt object model.

-

you can also run Powerpoint and select Tools | Macro | Visual Basic Editor
to bring up VBA editor (you must have a presentation open, btw). Then press F2 key to run the object browser
which shows all the methods for the powerpoint library and other
referenced libraries.

--

hope this help..

steve

sas

Re: Automating Office

sas22223-Jun-04 9:32

sas2222

3-Jun-04 9:32

and try this link to microsoft's docs...

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/modcore/html/deovrMicrosoftPowerPoint2000.asp

sas

Re: Automating Office

no_reg_name3-Jun-04 23:02

no_reg_name

3-Jun-04 23:02

Thanks.

I'm gonna try this and see how it goes. Smile | :)

Re: Automating Office

Rory Solley3-Jun-04 22:14

Rory Solley

3-Jun-04 22:14

MS Office actually comes with VB help in the form of .chm files although they are pretty well hidden. The path varies slightly from version to version but if you look around:

C:\Program Files\Microsoft Office\Office10\1033

(the 1033 is the important bit), you should see a bunch of .chm files. These will give you information on the various methods. It's not perfect, but it does help.

There is quite a bit of KB documentation on MSDN, lookup "Office Automation".

Re: Automating Office

no_reg_name3-Jun-04 23:01

no_reg_name

3-Jun-04 23:01

Yeah, I've seen the chm files, but they cover VB only. It is suprising, the lack of MFC samples. Frown | :(

Thanks anyway.

passing array to com Interface

smartcoder2-Jun-04 9:31

smartcoder

2-Jun-04 9:31

Hi,
I need to pass an array to a method in a com interface using variants. can anyone help me. i need to do in C++.

Re: passing array to com Interface

Andrew Quinn AUS3-Jun-04 4:18

Andrew Quinn AUS

3-Jun-04 4:18

Hi,

Do a search on the sites for SAFEARRAY (or if you're using ATL try CComSafeArray)

Hope this helps,
Andy

COM Interface Hooking

hardboy1111-Jun-04 9:13

hardboy111

1-Jun-04 9:13

Could someone in simple terms, explain Interface hooking using a COM component like MSN Messenger for example. What are the advantages of using COM interface hooking?

cheers

Confused | :confused:

mike

Re: COM Interface Hooking

Anonymous1-Jun-04 11:12

Anonymous

1-Jun-04 11:12

http://www.codeproject.com/com/cominterfacehookingpart.asp

firewall

shahrokh nabavi1-Jun-04 7:12

shahrokh nabavi

1-Jun-04 7:12

if i want to implement a firewall with windows apis for
processing each input/output packet please introduce me that apis (if there is)

koosha

handwritten signature authentication pro

yep yin31-May-04 20:49

yep yin

31-May-04 20:49

hello everyone. I am in deep sh*t now. i have to develop a biometric authentication system which apply neural network algorithm , that is using handwritten signatures to authenticate users instead of combination of user id and passwords. I do not even know which language to use, some told me MATLAB, some said VB. so can anyone give guidance or sample source code to me so that i do not need to start from scratch since the time is running out.
thanks a lot and please help pass this message around so that i can have more things to refer

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.