Re: Can we set a global hook in a COM object? - COM Discussion Boards

Re: What are the rules for changing a published COM interface?

Christian Graus21-Feb-05 15:31

21-Feb-05 15:31

Sir Garence wrote:
why I can't add new methods/properties to an interface?

If you add new methods, and keep the same GUID, you'll write code that starts up a COM object, based on that GUID, and will assume that method is there. for anyone who has your old component, the object will spin up, and blow up when that method is not there.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Re: What are the rules for changing a published COM interface?

Sir Garence22-Feb-05 4:25

Sir Garence

22-Feb-05 4:25

Hi Christian,

Thanks for responding.

My main concern - and this is the most likely scenario - is older apps running against the newer component. If I add new methods or properties to existing interfaces (but don't remove or change what was already there), will this cause any runtime issues?

Thanks again,

Gary

Re: What are the rules for changing a published COM interface?

Christian Graus22-Feb-05 8:41

Christian Graus

22-Feb-05 8:41

On that front, you should be fine. But murphys law states that the reverse scenario will bite you at some point.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

COM with C# multi client model

sokettepower20-Feb-05 23:50

sokettepower

20-Feb-05 23:50

Hi,

I'm discovering COM programmation. I've created a client - server application in .Net.
It works fine but for each client, a new server instance is created.
I would like to create only one instance of a server on a remote machine on which clientS could connect to it.

This is the site who helps me to create my client - server : http://my.execpc.com/~gopalan/dotnet/classic_com/com.net_quoteserver.html

Thks a lot

Denis

Re: COM with C# multi client model

vishalmore21-Feb-05 18:08

vishalmore

21-Feb-05 18:08

Hi sokettepower,

ur COM components appartment should be MTA (Multi-Threaded Appartment), I suppose !

Look out for more info. on STA, MTA and Proxy Stub.

Smile | :)

Cheers,
Vishal

Can we set a global hook in a COM object?

nadzzz20-Feb-05 7:24

nadzzz

20-Feb-05 7:24

in the SetWindowsHookEx function, I set the _pModule->get_m_hInst() as the HINSTANCE parameter.

The relust of this code is a local hook on the procedure.
"Global hook procedures should be placed in a separate DLL". is com is a separate DLL

hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL,
LowLevelKeyboardProc,
_pModule->get_m_hInst(),
0);

a related article is talking about the subject in a standart DLL (not COM).
http://www.codeproject.com/win32/AntonioWinLock.asp

Re: Can we set a global hook in a COM object?

Jörgen Sigvardsson20-Feb-05 9:02

Jörgen Sigvardsson

20-Feb-05 9:02

I don't see why it couldn't work. Why don't you just try it?

--
My name in Katakana is ヨルゲン.
My name in German is Jörgen.
My name in Mandarin/Kanji is 乔尔根西格瓦德森.

I blog too now[^]

Re: Can we set a global hook in a COM object?

vishalmore20-Feb-05 18:23

vishalmore

20-Feb-05 18:23

Hi nadzzz,

Is ur com object a dll ?
- If it is then u can't install global hook, to install global hook ur application must be an exe (rather than dll)
See the global hook docs for more info.
Smile | :)

Cheers,
Vishal

Error firing callback event

Mayur Mahajan19-Feb-05 19:03

Mayur Mahajan

19-Feb-05 19:03

My COM server should fire the event of a VB client. The code (generated by the Wizard) is as follows

HRESULT Fire_GetResult(VARIANT retResult)
{
CComVariant varResult;
T* pT = static_cast<t*>(this);
int nConnectionIndex;
CComVariant* pvars = new CComVariant[1];
int nConnections = m_vec.GetSize();
...
...

The problem here is that m_vec.GetSize returns 0 and hence the for loop to fire the event is not called and return value is 0xCCCCCCCC

However firing the event works intially and after a few function calls, it stops working!

I am totally confused what could the problem be. Is it because of some memory leak or anything else. Please comment on possible problems.

Also I would like someone to tell me whose responsibility it is to free the BSTR or VARIANT arguments in interface method, server or clients? for both by value and by reference type.
Thank You

Mayur Mahajan

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

IPropertyBag

nsrsetty18-Feb-05 18:33

nsrsetty

18-Feb-05 18:33

I have a problem. I need a COM dll, which takes a string as a filename and has to return a IPropertyBag by reading the file. The file may be simple text file, that consists a name value pairs. Once the file is read, the name value pair has to be added to the IPropertyBag. From the client I should be able to retrieve the name value information from the IPropertyBag.

The interface is defined like this
__interface IMetadataParser : IDispatch
{
[id(0), helpstring("method ParseMetadata")]
HRESULT ParseMetadata( [in] BSTR bstrXMLFilePath, [in,out] IPropertyBag** ppPropMetadataBag );
};

The client code looks like this.

hr = CoCreateInstance( CLSID_CMetadataParser, NULL, CLSCTX_INPROC_SERVER,
IID_IUnknown, (void**)&m_oMetadataParser );
CComObject<csubcomppropertybag> *pIOCRPropBag;
hr = CComObject<csubcomppropertybag>::CreateInstance(&pIOCRPropBag);
CComPtr<ipropertybag> pPropBg = NULL;
HRESULT hResStack = pIOCRPropBag->QueryInterface(IID_IPropertyBag, (void**)&pPropBg);
CComQIPtr<ipersistpropertybag> pISubPPB(m_oMetadataParser);
m_oMetadataParser->ParseMetadata(bstrXMLFilePath, &pPropBg1);

The definition of the class CSubCompPropertyBag is as follows:

typedef std::map<std::string, variant=""> PropBag;
typedef PropBag::iterator PropBag_IT;
typedef std::pair<std::string, variant=""> MapEntryPair;

CComModule _Module; //this should be in client

class ATL_NO_VTABLE CSubCompPropertyBag :
public CComObjectRootEx<ccomsinglethreadmodel>,
public IPropertyBag
{
public:

CSubCompPropertyBag()
{
ATLTRACE(_T("CSubCompPropertyBag is constructed \n"));
}

~CSubCompPropertyBag()
{

PropBag_IT bagIt = m_propBagMap.begin();
while(bagIt != m_propBagMap.end())
{
VARIANT varDel = bagIt->second;
if(VT_BSTR == varDel.vt)
::SysFreeString(varDel.bstrVal);
bagIt++;
}

m_propBagMap.erase(m_propBagMap.begin(), m_propBagMap.end());
ATLTRACE(_T("CSubCompPropertyBag is destructed \n"));
}

DECLARE_PROTECT_FINAL_CONSTRUCT()

DECLARE_NO_REGISTRY()

BEGIN_COM_MAP(CSubCompPropertyBag)
COM_INTERFACE_ENTRY(IPropertyBag)
END_COM_MAP()

//Method implement the IPropertyBag::Read() function
// move property value from private map to *pVar based on pVar->vt
//this function will be called from IPersistPropertyBag::Load() method
// for each property in ATL property map
STDMETHOD(Read)(LPCOLESTR pszPropName, VARIANT *pVar, IErrorLog *pErrorLog)
{
USES_CONVERSION;
if ((pVar == NULL) || (pszPropName == NULL))
return E_INVALIDARG;
std::string sPropName(W2A(pszPropName));
ATLTRACE("CFlowPropertyBag::Read() get called for property %s \n", sPropName.c_str() );
PropBag_IT bagIt = m_propBagMap.find(sPropName);
if (bagIt == m_propBagMap.end())
{
ATLTRACE("Fail to find the property %s in property bag\n", sPropName.c_str());
return E_FAIL;
}
else
{
try
{
VARIANT varValue = bagIt->second;

::VariantInit(pVar);
if(VT_ARRAY != varValue.vt)
{
HRESULT hr = ::VariantCopy(pVar,&varValue);
if(FAILED(hr))
throw E_FAIL;
}
else
{
SAFEARRAY *psaLanguage = varValue.parray;
pVar->vt = VT_ARRAY;
pVar->parray = psaLanguage;
}

ATLTRACE("Set property value from property bag completed\n");
return S_OK;
}
catch(...)
{
return E_FAIL;
}
}
}

//Method implement the IPropertyBag::Write() function
// move property value from *pVar to private map
//this function will be called from IPersistPropertyBag::Save() method
// for each property in ATL property map
STDMETHOD(Write)(LPCOLESTR pszPropName, VARIANT *pVar)
{
USES_CONVERSION;
if ((pVar == NULL) || (pszPropName == NULL))
return E_INVALIDARG;
std::string sPropName(W2A(pszPropName));
ATLTRACE("CFlowPropertyBag::Write() get called for property %s \n", sPropName.c_str() );
try
{
PropBag_IT bagIt = m_propBagMap.find(sPropName);
if (bagIt != m_propBagMap.end())
{
m_propBagMap.erase(bagIt);
}

VARIANT varVal;
::VariantInit(&varVal);

if(VT_ARRAY != pVar->vt)
{
HRESULT hr = ::VariantCopy( &varVal,pVar);
if(FAILED(hr))
throw E_FAIL;
}
else
{
SAFEARRAY *psaLanguage = pVar->parray;
varVal.vt = VT_ARRAY;
varVal.parray = psaLanguage;
}

std::pair<propbag_it, bool=""> ret =
m_propBagMap.insert(MapEntryPair(sPropName, varVal));
if (ret.second != TRUE)
throw E_FAIL;

ATLTRACE(_T("Write property into property bag completed\n"));
return S_OK;
}
catch(...)
{
return E_FAIL;
}
}
PropBag m_propBagMap;
};

Thanks in advance for the help.

COM Service

Vinicius Pontes18-Feb-05 0:04

Vinicius Pontes

18-Feb-05 0:04

Hi,

I have a COM service running under a W2000 machine.

I know the service starts when I turn the machine on, before I log on, but I would like to know how to get a notification that the user has logged on/off the machine.

Thanks in advance,

Vinicius

Re: COM Service

ThatsAlok19-Feb-05 6:04

ThatsAlok

19-Feb-05 6:04

Here you answer again
For that you have to write Winlogon Notification Package.
look for example here
http://www.codeproject.com/system/winlogon_notification_package.asp

"I Think this Will Help"
[Vote One Here,.....]
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alok="" gupta="" <br=""> visit me at http://www.thisisalok.tk

Re: COM Service

Vinicius Pontes20-Feb-05 23:38

Vinicius Pontes

20-Feb-05 23:38

Thanks!

Re: COM Service

ThatsAlok21-Feb-05 0:38

ThatsAlok

21-Feb-05 0:38

Thats Alright Buddy

"I Think this Will Help"
[Vote One Here,.....]
<h5
alok gupta="" <br=""> visit me at http://www.thisisalok.tk

Create a new Thread

BEamer17-Feb-05 2:25

BEamer

17-Feb-05 2:25

Hello,

i develop a printerui dll, that based on the com-interface. My problem is, that the com-object the threat, that i startet, terminated.

What can i do, that this problem is gone.

Thanks.

- Sorry for my bad english.

Excel COM

MJWhiteman217-Feb-05 0:44

MJWhiteman2

17-Feb-05 0:44

I'm trying to use some Excel COM from Visual C++, but am having difficulty calling certain functions. For example, take the WorkSheets.Add method. The function declaration is as follows:

LPDISPATCH Add(const VARIANT& Before, const VARIANT& After, const VARIANT& Count, const VARIANT& Type);

By looking in the Excel VBA Help, I can get documentation for this method:

Add Method (Worksheets Collection)

Creates a new worksheet. The new worksheet becomes the active sheet. Returns a Worksheet object.

Syntax

expression.Add(Before, After, Count, Type)

expression Required. An expression that returns a Worksheets object.

Before Optional Variant. An object that specifies the sheet before which the new sheet is added.

After Optional Variant. An object that specifies the sheet after which the new sheet is added.

Count Optional Variant. The number of sheets to be added. The default value is one.

Type Optional Variant. The sheet type. Can be one of the following XlSheetType constants: xlWorksheet, xlExcel4MacroSheet, or xlExcel4IntlMacroSheet. The default value is xlWorksheet.

Remarks

If Before and After are both omitted, the new sheet is inserted before the active sheet.

OK, now for some example code. I can add a new worksheet quite easily using the following code:

// After obtaining a Worksheets object, called ws:<br />
COleVariant VOptional((long)DISP_E_PARAMNOTFOUND, VT_ERROR);<br />
ws.Add(VOptional, VOptional, VOptional, VOptional

The problem is that this default usage inserts the sheet before all current sheets in my workbook, but I want to insert it after all the other sheets. In Excel VBA, I can do this by simply running:

Worksheets.Add.Move after:=Worksheets(Worksheets.Count)

However, I'm having real trouble finding what the data type of the 'After' argument needs to be in C++ and I can't find any sample code anywhere! I have found hundreds of examples passing numbers or strings, but not objects! Can anyone supply some sample code?

Using the _Worksheet.Move method would also accomplish the same thing, but I have the same problem, so any help would be greatly appreciated!

Re: Excel COM

MJWhiteman217-Feb-05 3:27

MJWhiteman2

17-Feb-05 3:27

Just in case anyone needs to do this, I figured out how to do it. The 'after' parameter needs to represent the IDispatch pointer of the worksheet you want to add the new sheet after. So you have to do something like this:

	// Create a COleVariant to reference an object. The m_lpDispatch member gives a<br />
	// pointer to the IDispatch interface of an object. The type must be VT_DISPATCH<br />
	COleVariant var;<br />
	var.vt = VT_DISPATCH | VT_BYREF;<br />
	var.ppdispVal = &(objSheet.m_lpDispatch);<br />
<br />
	// Add the new sheet AFTER the sheet referenced in 'matt'<br />
	sheet = objSheets.Add(VOptional, var, VOptional, VOptional);

In the above, objSheets is of type Workbooks and objsheet and sheet are of type _Worksheet

Interprocess communication

ravishanker16-Feb-05 17:17

ravishanker

16-Feb-05 17:17

I have a windows service which creates another process after it is started. Now in the process that is created i create a COM object with an interface and few methods on it. Now if I run the Service with a Login I can access the interface of the COM object by regisrtering the interface in running object table and then getting it from there in the main service.
How ever if I run the servcie with LocalSystem account I cannot get the Interface pointer from the Running object table

What could be the problem? Is there another way of doing this

Thanks
Ravi

MSComm32 dependances

Trankil16-Feb-05 6:26

Trankil

16-Feb-05 6:26

Hi !

(Excuse-me, I hope that this message, will not be inserted inside the current discussion . I want to post a new message, a new discussion, but I don't know how to do.Here is my purpose)

I have developped a software which manage modem through serial

communications. That is why, I have imported the component MSComm32.ocx

in my application.

I have used .NET for my purpose . The installer application is

defined to register the component MScomm32 into the computer (A) on

which we make the installation. At this stage, there is no problem, the

installation of my application is successful. But when I launch my

application, there is a fail;

N.B. : The component MSComm32.ocx is inside the environnement Visal

Basic 6.0 , but not inside Visual Basic .NET developpement environment.

After the fail, I have installed VB 6.0 on the computer (A). And

now, the launch is successful. I have realized that, at run, the

component MSComm32.ocx refers another components (DLL), inside VB 6.0

So , my probelm I want to figure out is this : what are the satellite

components of MsComm32.ocx ? What am I going to do, to list all thise

components ?

Re: MSComm32 dependances

rwestgraham16-Feb-05 16:43

rwestgraham

16-Feb-05 16:43

Look in the module MSComm32.dep. It require comcat.dll and also optionally other components for support of languages other than english.

Since you are using the control in VB.NET you must also insure that the Interop assembly(s) for the control are also installed!

Hope this helps,

Robert

Who have the SkinCrafter dll ?

rushing15-Feb-05 22:16

rushing

15-Feb-05 22:16

The version without popup window?
Thanks!

restore IXMLDOMElement from pointer

Konrad Windszus15-Feb-05 1:18

Konrad Windszus

15-Feb-05 1:18

I want to write a simple XML editor with the help of MSXML. I'm using the library with smart pointers. I can read out the xml file and can display its structure within a treectrl, but I want to store a pointer to the specific element in the ItemData (DWORD) of the according treectrl item. What do I have to store (Interface*, IXMLDOMElementPtr) and how do I create the IXMLDomElement from that pointer? Do I have to care about releasing/allocating memory? Sorry for that silly question, but I don't have much experience with COM.
Thank you very much in advance,
Konrad

MS word

merlinos14-Feb-05 14:43

merlinos

14-Feb-05 14:43

Does anyone know if it is possible to store a custom object inside a word document?

Let's say for example that I would like to save inside a word document the ID of the machine the document was created on. That information would be hidden from the user but stored inside the word document and could be retrieved programatically.

Help... Anyone?

Thanks,
Merlinos

IDTExtensbility2 add-in deployment

m6reid14-Feb-05 11:10

m6reid

14-Feb-05 11:10

Hi,

I hope this post belongs here...it seems to me to be some sort of COM issue, so here goes...

I have been working on a .NET add-in for Word 2003. I have created the project as a "Shared Add-in" according to this tutorial:

http://support.microsoft.com/kb/302896/EN-US/

My problem is that when I run the installer for this add-in on a machine other than the development machine it doesn't show up in Word.

The generated MyAddinSetup project doesn't seem to install the add-in correctly. I've tried both "For everyone" and "For this user only" to no avail.

I've also tried using regasm to register the .dll in the registry on the test machines, but nothing seems to work.

I've verified that both the Addin and the AddinSetup projects reference the Office 2003 PIAs; basically everything I've been able to pull up on the subject.

I've still yet to get this thing to run on any machine that doesn't have Visual Studio .NET 2003 installed. I have ensured that my test machines do have the .NET framework v1.1 installed, and that Office 2003 was installed with the .NET programmability feature enabled.

Has anyone had similar problems? Am I missing something obvious?

Any help is appreciated.
Thanks.

Re: IDTExtensbility2 add-in deployment

vishalmore21-Feb-05 18:52

vishalmore

21-Feb-05 18:52

Hi m6reid,

Are you registering this add-in in restricted user mode on Win2K ?

Cheers,
Vishal

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