How to SendMessage to a windowless Ctrl - COM Discussion Boards

safee ullah27-Jul-03 21:14

27-Jul-03 21:14

hi there..

i am working on a spread sheet control..and need to know if there is any problem with the way i am returning from the Invoke call..

When run this method throws an access violation...any ideas.??

here is the code..

long CControl :: GetObjCellCol(long ObjID)
{
DISPPARAMS DispParam1;
EXCEPINFO excep;
UINT nArgErr;
DISPID dispidNamed;
VARIANT * pResult = NULL;

DispParam1.cArgs = 1; //number of arguments
DispParam1.cNamedArgs = 0; // named arguments.
DispParam1.rgdispidNamedArgs = &dispidNamed;
// Dispatch IDs of named arguments.

DispParam1.rgvarg = new VARIANTARG();

DispParam1.rgvarg->vt = VT_I4;
DispParam1.rgvarg->lVal = ObjID;

IImpl::Invoke(DISPID_F1_CellCol, IID_NULL , 0 , NULL, &DispParam1,pResult , &excep, &nArgErr);
return pResult->lVal;
}

Re: how to return from IDispatch invoke?

Mike Dimmick28-Jul-03 2:27

Mike Dimmick

28-Jul-03 2:27

pResult is NULL. You should be passing the address of a valid VARIANT structure, i.e.:

VARIANT vtResult = { 0 };
 
// ...
 
IImpl::Invoke( 
    DISPID_F1_CellCol,
    IID_NULL,
    0,
    NULL,
    &DispParam1,
    &vtResult,
    &excep,
    &nArgErr 
);
 
return vtResult.lVal;

When the called component comes to fill in the result value, it tries to write through a NULL pointer and causes the access violation.

Hope this helps.

Re: how to return from IDispatch invoke?

safee ullah28-Jul-03 2:53

safee ullah

28-Jul-03 2:53

oooooooooops
thanks Smile | :)

)

BHO

manuboy27-Jul-03 11:56

manuboy

27-Jul-03 11:56

I'm relatively new to c++ / com. I'm attempting to use a BHO in an intranet environment to add headers to specific urls. My problem is that using the code below, my new header doesn't turn up at the server (testing with an asp page that dumps all headers + an IP packet sniffer).

USES_CONVERSION;<br />
HRESULT hr ;<br />
<br />
if (pDispParams->cArgs >= 5 && pDispParams->rgvarg[5].vt == VT_BYREF|VT_VARIANT))<br />
{<br />
      CComVariant vtURL(*pDispParams->rgvarg[5].pvarVal);	<br />
      vtURL.ChangeType(VT_BSTR);<br />
<br />
      if (strstr(OLE2CA(vtURL.bstrVal), urlSearchList))<br />
      {<br />
	// cancel the navigation<br />
	pDispParams->rgvarg[0].boolVal = VARIANT_TRUE;<br />
<br />
	// send stop to browser<br />
	hr = m_spWebBrowser2->Stop();<br />
	if (FAILED(hr))<br />
 	  return hr;<br />
<br />
	CComBSTR    bstrHeaders("NewHeader: Header1\n\r");<br />
	CComVariant newUrl(vtURL.bstrVal);<br />
	newUrl.ChangeType(VT_BSTR);<br />
			<br />
	CComVariant vHeaders(bstrHeaders.m_str);<br />
	vHeaders.ChangeType(VT_BSTR|VT_BYREF);<br />
	<br />
        // navigate!<br />
	hr = m_spWebBrowser2->Navigate2(&newUrl, NULL, NULL, NULL, &vHeaders);<br />
	if (FAILED(hr))<br />
	  return hr;<br />
      }<br />
  }

The MSDN docs for the naviagte2 method show the headers arg as being pointer to variant. Am i using the wrong type?

Any links, code, or pointers much appreciated... WTF | :WTF:

::Confused

Re: BHO

Michael Dunn27-Jul-03 12:07

Michael Dunn

27-Jul-03 12:07

You don't need this line:

vHeaders.ChangeType(VT_BSTR|VT_BYREF);

because you're using the CComVariant ctor that makes it a string. (And BTW the type is VT_BSTR not VT_BSTR|VT_BYREF).

--Mike--
Ericahist | Homepage | RightClick-Encrypt | 1ClickPicGrabber
Latest art~!@#2rDFA#@(#*%$Rfa39f3fqwf--=
NO CARRIER

Re: BHO

manuboy27-Jul-03 12:12

manuboy

27-Jul-03 12:12

Thanks Michael, i should have seen that ... unfortunately using just VT_BSTR (which i began with before i got desperate and just started experimenting) doesn't solve the problem.

Is there a way to determine what field of the struct to load when the documentation just says Variant *??? Or is the data type not really my problem?

Getting selected folder in a namespace extension

Mike Hartway25-Jul-03 14:28

Mike Hartway

25-Jul-03 14:28

I am implementing a namespace extension and I need to be able to determine what item is selected in the tree view (left hand pane in explorer) which is an IShellFolder implementation.

I can get the selection notification in the listview (right hand pane) in my implementation of IShellView via the IShellView's WndProc callback, but I can find no such mechanism in the IShellFolder.

Is there another interface in addition to IShellFolder that I need to implement in order to get this info or am I just missing something more obvious?

Many thanks!

Mike Hartway

How to SendMessage to a windowless Ctrl

ray_li25-Jul-03 5:41

ray_li

25-Jul-03 5:41

Hi! everybody:

I'm developing a ActiveX control which is a windowless, If I find something special in my class, I want to SendMessage to this ctrl and let it do something , but I can not get the window handle of this ctrl, so this ctrl also can not get this message.(I have tried AfxGetMainWnd, it doesn't work)

Does anyone has similar experience? Plesae give me some ideas, I'll appreciate
your help.

Ray

Re: How to SendMessage to a windowless Ctrl

John M. Drescher25-Jul-03 6:54

John M. Drescher

25-Jul-03 6:54

ray_li wrote:
I have tried AfxGetMainWnd, it doesn't work

If your control is windowless there is no window handle so AfxGetMainWnd will not work...

John

Re: How to SendMessage to a windowless Ctrl

MartinOrtiz31-Jul-03 12:24

MartinOrtiz

31-Jul-03 12:24

Why use SendMessage??? Won't a regular COM method be sufficient, and easier??

If you you need to use SendMessage, make it a window control and check off the : "invisible at runtime" option

COM+ / MSMQ

sam_jr24-Jul-03 17:05

sam_jr

24-Jul-03 17:05

Is MSMQ merged with COM+?

COM+ = COM + MTS + MSMQ
or
COM+ = COM + MTS

Confused | :confused:

Re: COM+ / MSMQ

ICBM25-Jul-03 15:02

ICBM

25-Jul-03 15:02

COM+ contains a superset of the functionality of MTS. In the case of MSMQ, the concepts and implementation are considerably different in COM+ than in the original MSMQ. In the original, all objects had to know that they were supporting MSMQ, and had to agree message formats etc. In COM+, use of asynchronous calls is more of less invisible to the client.

Get hold of a copy of COM and .NET Component Services by Juval Lowy. It's available online at http://safari.oreilly.com too.

Closing document in Word under Automation

Dave Loeser24-Jul-03 4:52

Dave Loeser

24-Jul-03 4:52

I'm using Word Automation (using C++ here) as an out of proc exe to Find and Replace text within documents. When I create an instance of Word I would prefer to keep that instance open and then open, search/replace, close and repeat until I am finished with all documents and then quit the word application instance.

I have this working but I have an odd (or maybe it is a common) problem. When I close the document, Word becomes visible. Here's how I am closeing the document.

void CMSWord9Automation::CloseDoc()
{
	try
	{
		if(m_pOpenDoc) // Word::_DocumentPtr
		{
			//m_pWord->Visible = VARIANT_FALSE; // Does not work
			m_pWord->Documents->Close(
				&_variant_t(Word::wdDoNotSaveChanges),
				&_variant_t(vtMissing),
				&_variant_t(VARIANT_FALSE));

			//m_pWord->Visible = VARIANT_FALSE; // This resets word to invisible but isn't really the desired approach
			m_pOpenDoc.Release();
		}
	}
	catch(_com_error& ComError) 
	{
		DumpComError(ComError);
	}
}

I'm looking for any information on how to stop Word from displaying when I close the opened document.

Thanks,

Dave Dak Lozar Loeser
When access is allowed to a member, it said to be accessible. Otherwise, it is inaccessible. - MSDN:C# Programmer's Reference

word automation

Jason Henderson23-Jul-03 10:06

Jason Henderson

23-Jul-03 10:06

How can I take an instantiated Word document object and open it in a container item? I'm using COleClientItem::CreateFromFile, but if the document has a password it opens the word application, and I don't want that to happen.

So, I'd like to take my Word::_DocumentPtr that is already open and move it into my container item. Any ideas?

If that's not possible, how should I open the document without the password? I have tried opening it using Word.Application and then setting the password and saving, but the password doesn't seem to be set to "" when I open it again. Here's what I'm doing now:

BOOL CDocContainerCntrItem::Create(LPCTSTR lpszPath)
{
	USES_CONVERSION;
<br> <br>
	BOOL bRetVal = FALSE;
	SCODE sc = 0;
<br> <br>
	// get storage for the object via virtual function call
	m_dwItemNumber = GetNewItemNumber();
	GetItemStorage();
<br> <br>
	// add AfxOleInit(); in CXOfficeApp::InitInstance
	AfxOleGetMessageFilter()->EnableNotRespondingDialog(FALSE);
<br> <br>
	// attempt to create the object
	LPOLECLIENTSITE lpClientSite = GetClientSite();
<br> <br>
	if (strcmp(lpszPath, "") != 0)
	{	
		Word::_ApplicationPtr app;
		HRESULT hr = app.CreateInstance("Word.Application");
<br> <br>
		if (SUCCEEDED(hr))
		{
			if (app != 0)
			{
				COleVariant vtOptional((long) DISP_E_PARAMNOTFOUND, VT_ERROR);
				COleVariant vtFileToOpen(lpszPath);
				COleVariant vtPwd("MYPASS");
				COleVariant vtPwdNew("");
<br> <br>
				Word::_DocumentPtr doc = app->Documents->Open(vtFileToOpen, vtOptional, 
					vtOptional, vtOptional, vtPwd);
<br> <br>
				doc->put_Password(_bstr_t(""));  // trying to set the password
				doc->Password = L"";  // this doesn't work either
<br> <br>
				if (SUCCEEDED(doc->SaveAs(vtFileToOpen, vtOptional, vtOptional, vtPwdNew)))
				{
					doc->put_Saved(VARIANT_TRUE);
					doc->Close();
				}

				doc = NULL;
<br> <br>
				bRetVal = CreateFromFile(lpszPath);
			}
		}
<br> <br>
		app = NULL;
	}
	else
	{
		CLSID clsid;
		CLSIDFromProgID(L"Word.Document", &clsid);
		
		bRetVal = CreateNewItem(clsid);
	}
<br> <br>
	return bRetVal;
}

Any help is greatly appreciated!

Jason Henderson

I bleed orange.

Arrays of IUnknown..

ICBM22-Jul-03 0:27

ICBM

22-Jul-03 0:27

Hello all

What I am trying to do is implement a function in an ATL COM server that returns an array of objects. I need to be able to use these objects from VB. My searches on the net turned up lots of references to using SAFEARRAY(VARIANT), but very little sample code. Ideally, I'd love a link to some code that declares a method like
GetObjects([in,out] SAFEARRAY(VARIANT) *ppObjects)

and shows both the implementation in C++ (including creating and populating the SAFEARRAY with IUnknown-derived object pointers) and some calling code, either in VB or C#.

Thanks all

Ian

Re: Arrays of IUnknown..

valikac22-Jul-03 8:56

valikac

22-Jul-03 8:56

There are some good examples here at CodeProject. Look under the beginner section.

http://www.codeproject.com/com/

Kuphryn

Re: Arrays of IUnknown..

first_sandy25-Jul-03 3:40

first_sandy

25-Jul-03 3:40

Hi Ian,

You can create a safe array of variants and then put the array in the variant and pass to the client.
Like :
SAFEARRAY *pSA =NULL;
SAFEARRAYBOUND sabound;
sabound.cElements = nCount; //Array size.
sabound.lLbound = 0;

pSA = SafeArrayCreate(VT_VARIANT, 1, sabound);
long nIterator = 0;
//in a loop put the values.
hr = SafeArrayPutElement(pSA, nIterator, (void *)&vaPutValue);
VARIANT vaResult;
VariantInit(&vaResult);

V_VT(&vaResult) = VT_ARRAY | VT_VARIANT;
V_ARRAY(&vaResult) = pSA;

return vaResult;

At client side, you can write it like:

Dim vaDocList as Variant

vaDocList = m_pClass.GetArray() 'm_pClass is the reference to co-class.
get bounds like
nUBound = UBound(vaDocList)
nLBound = LBound(vaDocList)

in a loop get values in the variables as per ur requirement.
i feel it will help you.

Blush | :O

sandy

Last night i realized, i was seeing a dream in my dream.

Re: Arrays of IUnknown..

ICBM25-Jul-03 13:44

ICBM

25-Jul-03 13:44

Thanks very much for that, just what I was after Smile | :)

How to prevent binding a Type library to a ATL Attributed DLL ?

talhalfon21-Jul-03 22:39

talhalfon

21-Jul-03 22:39

How to prevent binding a Type library to a ATL Attributed DLL ?

need help

ty
tal halfon

IE plugin

nettrinity20-Jul-03 17:04

nettrinity

20-Jul-03 17:04

I want to write a Internet Explorer embeded Text editor for a government document transfer system. I want it embed in to IE, just like those online virus scan...ETC. when you first use it, a dialog box popup asking you whether or not the program is allowed to run. I bet it was probably a activeX control (ocx)?, right?(curret me, I am wrong Smile | :)

)

but I don't know how. It must ba a lot different from writing win32 application.(i am new to ie plugin Smile | :)

)
can anybody tell me where I can find some documents regarding this?
And is it a really a activeX control?

even a link or a book name will help!

thanks in advance!

xushenxin
keep fighting and you will win!

Re: IE plugin

ashxly21-Jul-03 18:41

ashxly

21-Jul-03 18:41

try to use atl com, create a internet browse object
for more detail ,plz check the msdn.

Re: IE plugin

nettrinity21-Jul-03 21:35

nettrinity

21-Jul-03 21:35

OK ,I'll check it out, thanks!: Roll eyes | :rolleyes:

)

xushenxin
keep fighting and you will win!

Re: IE plugin

ashxly21-Jul-03 18:41

ashxly

21-Jul-03 18:41

try to use atl com, create an internet browse object
for more detail ,plz check the msdn.

OCX issue

carb18-Jul-03 9:58

carb

18-Jul-03 9:58

Hello:

My first post so apologies if I've put this in the wrong place or broken some (n)etiquette.

I'm using a grid control .ocx file from inside an MFC app; all C++, built under VC++ 6.0. It has worked fine since
1999 but now is starting to cause problems on Win2000 machines (shows up in all service packs). The identical code works fine under Win98, so I'm guessing it's an upgrade issue.

All the dialogs I try to launch via the ocx fail with the following error message in Visual C++ 6.0 (cut and pasted from the Debug window):

CoCreateInstance of OLE control {A8C3B720-0B5A-101B-B22E-00AA0037B2FC}
failed.
>>> Result code: 0x80040154
>>> Is the control is properly registered?
Warning: CreateDlgControls failed during dialog init.

The control is registered properly via regsvr32 before running the app.

The above error message appears on the call to:

hWnd = ::CreateDialogIndirect(hInst, lpDialogTemplate,
pParentWnd->GetSafeHwnd(), AfxDlgProc);

in CWnd::CreateDlgIndirect(), called from CDialog::DoModal() in the usual way.

The behavior seen in release versions is that no dialog appears in response to user action (menu choice, etc).

I know next to nothing about COM/ActiveX/OLE objects, so if there's either a quick fix, or an explanation why this would happen (so I can stop the wild goose chase), I'd appreciate it.

The original supplier of this commercial ocx can't supply an update.

I hope this is enough info; it's all I can share.

Thanks,
-Chuck.
C J Charbonneau
Ottawa, Canada

Getting an Explorer history item URL

yarp18-Jul-03 0:06

yarp

18-Jul-03 0:06

I'm implementing a web navigator application and I'm currently working on the history items. Does anybody know how I can get the URL pointed to starting from the item pidl ?
Thanks in advance,

Yarp
http://www.senosoft.com/

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