How to solve this problem??? - COM Discussion Boards

Re: How to add a popup menu into Explorer Bar ActiveX Control?

Amit Dey27-Apr-02 19:21

27-Apr-02 19:21

checkout
toolband -http://www.codeproject.com/useritems/toolband.asp

dropdown menu/toolbar-http://www.codeproject.com/wtl/toolbar.asp

and Bjarne Viksoe's website www.viksoe.dk for full code samples of explorer bars,toolbands etc.

#define MOSTLY_LEAN_AND_MEAN

ATL-based subclassed windowed control flickers on resize

Mr Matt Ellis, Esq23-Apr-02 5:39

Mr Matt Ellis, Esq

23-Apr-02 5:39

Hi folks. I've created an ATL control that subclasses the standard treeview. It's very nice and I can host it in a web page and everything. The problem is when I resize the web page (with full window drawing as it's resized) I get a really bad flicker of the tree view. Something is causing my control to erase. I've tried suppressing WM_ERASEBKGND, but no good. When ATL resizes the main window of my control with SetWindowPos, it gets erased. If I make a windowless control (just using the default drawing from the wizard) I get flicker free resizing.

Does anyone know how I can get rid of flicker for the windowed control?

Thanks
Matt

How to use COM Objects in VC++ - Please Help

23-Apr-02 1:33

I ve downloaded a Flash Com Objects from http://bukoo.sourceforge.net. I ve registered the dll. Then i imported the dll in VC. Please anyone explain how to use the COM object.

ThankYou

Re: How to use COM Objects in VC++ - Please Help

Paul M Watt24-Apr-02 8:27

Paul M Watt

24-Apr-02 8:27

You will either need a header file that indicates the interfaces for the object, or the DLL needs to contain a typelibrary. If the DLL contains a type library you can use the #import command at the top of your file to automatically extract the data and create a header file for you. Look up the #import command in MSDN.

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

How to use COM Objects in VC++

23-Apr-02 1:32

I ve downloaded a Flash Com Objects from http://bukoo.sourceforge.net. I ve registered the dll. Then i imported the dll in VC. Please anyone explain how to use the COM object.

ThankYou

Re: How to use COM Objects in VC++

ThatsAlok19-Jul-09 0:18

ThatsAlok

19-Jul-09 0:18

Anonymous wrote:
I ve downloaded a Flash Com Objects from http://bukoo.sourceforge.net. I ve registered the dll. Then i imported the dll in VC. Please anyone explain how to use the COM object.

I think you have to look for some beginner books

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

How to generate a real certificate

liuage22-Apr-02 17:27

liuage

22-Apr-02 17:27

Dear all:

I generated a test certificate by the following command :

makecert -sk test1 -r -ss test.

I want to generate a real certificate,could you give me some advice.

thanks a lot.

liuage Confused | :confused:

How to solve this problem???

chq1222-Apr-02 6:37

chq12

22-Apr-02 6:37

I wrote a method in COM, has two parameters, BSTR bstrUserID and BSTR bstrUserPwd. I set type in SQL Server as varchar, I used stored procedure to execute a search in database.

Method:

STDMETHODIMP CStudentManager::LogOn(BSTR bstrUserID, BSTR bstrUserPwd)
{
// TODO: Add your implementation code here

BSTR UserID = ::SysAllocString(L"UserID");
BSTR UserPwd = ::SysAllocString(L"Passward");

VARIANT vUser, vPassword;
vUser.vt = VT_BSTR;
vUser.bstrVal = bstrUserID;
vPassword.vt = VT_BSTR;
vPassword.bstrVal = bstrUserPwd;
m_Comm->CommandText = L"LogOn";
HRESULT hr = AppendParameter(UserID, adChar, vUser, adParamInput,20);
if(SUCCEEDED(hr))
hr = AppendParameter(UserPwd, adChar, vPassword, adParamInput,20);
if(SUCCEEDED(hr))
m_Comm->Execute(pvtEmpty1, pvtEmpty2, adCmdText);

if(hr == 0)hr = S_OK;
else hr = E_FAIL;

m_Comm->Parameters->Release();
m_pRs->Close();
::SysFreeString(UserID);
::SysFreeString(UserPwd);

return hr;
}

Stored Procedure:
Create Procedure LogOn
(
@ID,
@Password
)
as
if EXISTS(Select userid from users where userid = @ID and userpwd = @Password
return 0
else
return 1

Go

I used a client function to logon: hr = pManager->LogOn(LogonID, LogonPwd);
I found the function can work, but always return E_FAIL even when database has userid and password.
I thought there is some wrong in define the type, but I can not find it out.

So could anyone tell me when I used BSTR in COM and varchar in SQL SERVER, what should i pay attention to ?

Re: How to solve this problem???

Vi223-Apr-02 6:11

Vi2

23-Apr-02 6:11

chq12 wrote:

BSTR UserID = ::SysAllocString(L"UserID");
...
HRESULT hr = AppendParameter(UserID, adChar, vUser, adParamInput,20);
...
Procedure LogOn(@ID,...

Is it the valid relation between "UserID" and "ID"? Is it the same parameter?

With best wishes,
Vita

Re: How to solve this problem???

chq1223-Apr-02 12:58

chq12

23-Apr-02 12:58

Yes, it is. Should these two be same? I mean, if I use UserId in COM as the parameter name, so I should use @UserID in stored procedure. Is it right?

Re: How to solve this problem???

Vi223-Apr-02 21:05

Vi2

23-Apr-02 21:05

I think that they must be the same. Try it.

With best wishes,
Vita

IPictureDisp with copy constructor

21-Apr-02 1:27

I'll create a IPictureDisp dervied class with a copy constructor, to insert LPPICTUREDISP in an array as follows:

OCArray<picturedisp> m_Pics;
m_Pics.Add(new PICTUREDISP(*pPic));

The point is, that the derived class I has created don't works. Maybe someone can write an example?

thx
Martin

Re: IPictureDisp with copy constructor

Vi223-Apr-02 21:25

Vi2

23-Apr-02 21:25

While you are working with the interfaces, you should not try to copy the content of the interface pointer, i.e. *pPic.

To copy the object, you MUST use the copy of pPic, i.e. IPictureDisp* pPicNew = pPic; pPicNew->Addref(); and pPicNew->Release(); after the stopping of its usage.

You should implement the member OCArray::Add(IPictureDisp* pPic) under above requirements and use m_Pics.Add( pPic );

With best wishes,
Vita

Re: IPictureDisp with copy constructor

26-Apr-02 0:25

I've already done, that don't works.
is there another way to do it?

thx
Martin

Re: IPictureDisp with copy constructor

Vi226-Apr-02 23:45

Vi2

26-Apr-02 23:45

And what is wrong? Let us look at your PICTUREDISP constructors/destructor. Also, what is a OCArray class?

With best wishes,
Vita

Re: IPictureDisp with copy constructor

27-Apr-02 1:59

The OCArray is a faster CArray class (you can find it on this page).

The variable pPic is a LPPICTUREDISP an is passed by a function called from a VisualBasic application. (It is only a temporary variable).

It should work like that:
1. pPic is passed to the function
2. the function inserts the pPic into the array
3. and calls a function that updates the thumbnail view.

The point is that you can only insert two pic's, if you'll insert a third one the ocx crashes. Furthermore all pictures become the last inserted picture.

The declaration of LPPICTUREDISP is the standard MFC declaration.

The two files of my PICTUREDISP class can you find on:
http://www.martin.krellmann.net/PICTUREDISP.h.txt
http://www.martin.krellmann.net/PICTUREDISP.cpp.txt

Re: IPictureDisp with copy constructor

Vi227-Apr-02 4:11

Vi2

27-Apr-02 4:11

Well. I have a look at your files.

PICTUREDISP(IPictureDisp* lpDisp)
{
    if (this != NULL)
        this->Release();

    if ((lpDisp != NULL) &&
        SUCCEEDED(lpDisp->QueryInterface(IID_IPictureDisp, (LPVOID*)this)))
    {
        ASSERT(this != NULL);
    }
}
ULONG STDMETHODCALLTYPE PICTUREDISP::Release()
{
    return this->Release();
}

Why have you decide to call the Release() in the constructor? You must get the endless loop, IMHO.

virtual ~PICTUREDISP();

You should not use the virtual destructor. Your vtable will not correspond to the vtable of a class PICTUREDISP during a destructor call (QueryInterface will replace this vtable).
To avoid the AddRef/Release problem you must also realize the operator of copying with your technique.

PICTUREDISP& operator=(const PICTUREDISP& src)
{
    ...
}

In summary I would like to tell you that your technique is very doubtful and is fraught with mistakes. Though it may have the right on life. Be attentive! And often use Debug Session!

With best wishes,
Vita

Re: IPictureDisp with copy constructor

27-Apr-02 5:48

I think that is to difficult for me. Maybe you could modify my source-files an mail them to me: martin2002@web.de.

Is there a better technique to relaize the view. Well pherhaps it is a good way in VB, but maybe not in C++? So you could figure out that I'm quite a good VB programmer, but these MFC/COM/ATL thing are to difficult for me yet. But it is very necessary to realize the thumb view.

Please help me ... Smile | :)

How to use an activex when user does not have an administrator account ?

Jean-Michel LE FOL19-Apr-02 23:17

Jean-Michel LE FOL

19-Apr-02 23:17

I wrote an ActiveX. It is included in an HTML page with a codebase information used to install the ActiveX on the user machine.
When the user has an administrator account (WinNT and Win2000) or an account with rights, it works. Else, the ActiveX is not instanciate in the HTML page.

Does anybody know how to force the install of an ActiveX with a standard Windows user account ?

Linker Error

Madmaximus19-Apr-02 4:20

Madmaximus

19-Apr-02 4:20

Hi,

I get a linker error when I try to compile this class that contains a sink object in my ATL COM project.
"error LNK2005: "struct ATL::_ATL_FUNC_INFO OnNewUpdateInfo" (...) already defined in EventClient.obj"

Here is the listing of the Header file that conatians the sink object.
// EventClient.h: interface for the EventClient class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_EVENTCLIENT_H__062FDEBD_52F0_11D6_97B4_0002A5A9B5AA__INCLUDED_)
#define AFX_EVENTCLIENT_H__062FDEBD_52F0_11D6_97B4_0002A5A9B5AA__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#import "D:\TreeServer\TreeServer.tlb" no_namespace, named_guids, raw_interfaces_only, raw_native_types

//#include "D:\TreeServer\TreeServer.h"
//#include "D:\TreeServer\TreeServer_i.c"

#include <windows.h>
#include <atlbase.h>
#include <atlcom.h>

/************************************************************/

// Info for the events handler.
ATL::_ATL_FUNC_INFO OnNewUpdateInfo = {CC_STDCALL, VT_EMPTY, 1, {VT_BSTR}};

class CEventClient
: public IDispEventSimpleImpl<1, CEventClient, &DIID__ITreeUpdateEvents>
{
public:
CEventClient(ITreeUpdate *pITreeUpdate);
virtual ~CEventClient();

// The sink method.
void __stdcall OnNewUpdate(BSTR msg)
{
USES_CONVERSION;
m_bstrInMsg = msg;
SysFreeString(msg);
}

BEGIN_SINK_MAP(CEventClient)
SINK_ENTRY_INFO(1, DIID__ITreeUpdateEvents, 1, OnNewUpdate, &OnNewUpdateInfo)
END_SINK_MAP()

private:
ITreeUpdate *m_pITreeUpdate;
BSTR m_bstrInMsg;
};

#endif // !defined(AFX_EVENTCLIENT_H__062FDEBD_52F0_11D6_97B4_0002A5A9B5AA__INCLUDED_)

Any help would be great. Wink | ;-)

I've been trying to track down this error for days now. ;(

Thanks in advance.
Ken

Re: Linker Error

Tim Smith19-Apr-02 4:25

Tim Smith

19-Apr-02 4:25

You variable is in the H file, thus being declared twice. Place an extern in the H file and the actual variable in a CPP.

Tim Smith

I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?

CComPtr

19-Apr-02 2:57

Hi!

I am a developer and I work with DCOM on Windows98. The question is: is there any problem to use a CComPtr object as a class member?

Thanks.

Gian.

Re: CComPtr

Tim Smith19-Apr-02 3:34

Tim Smith

19-Apr-02 3:34

Nope, not at all. I use it all the time.

The only problem I have ever seen with CComPtr is that it doesn't work in STL collections. But there is a CAdapt class that helps with this problem.

Instead of std::vector <ccomptr <isomething=""> >, you have std::vector <cadapt <ccomptr="" <isomething=""> > >.

Tim Smith

I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?

Returning values from COM object ??

19-Apr-02 1:37

Hi everybody,

I'm a complete COM beginner and I'm wrestling with my first project using MSVC.
Using the ATL wizard I can successfully create a simple DLL (add simple ATL object, AddMethod).
My problem is how can I return a value from my method ? I DO NOT want to pass pointers, which I then manipulate within the method but I want to be able to return the value "directly" (retVal = obj.mymethod()). I'm sure this can be done, but it seems the return type of COM methods is always HRESULT !??
Can I do this using properties (AddProperty) ?
A few lines of example code would be great.

Many thanks,

Axel

Re: Returning values from COM object ??

Paul M Watt21-Apr-02 9:39

Paul M Watt

21-Apr-02 9:39

It is completely possible to create a COM interface function that returns the value directly like this:

DWORD GetCount();

However, I would only recommend doing this if you are only writing this object for use in your programs, and you will be using the object as an INPROC_SERVER.

If you want to write COM objects that are truely binary compatible, and can be used by other languages than C++, like VB, then you will need to alway return HRESULT. The reason why is for programs that perfrom network or interprocess communication through COM objects. Whenever you expand the boundaries of your program, there are certain situations that can occur that are out of your control, like the user disconnects their computer from the network. The other libraries that COM depends on will use the HRESULT to indicate this to your program or the program that is using your object.

If you do not use pointers to return values to the user, it becomes more difficult to marshal your data across process boundaries and computers.

Here is a simple prototype for a Get procedure:

HRESULT __stdcall GetCount(DWORD *dwCound);

You want to use the stdcall calling convention for all of your functions in COM, because this is the convention that all programs expect when dealing with a COM interface. _cdecl is the default for VC++.

The bool Essential COM,/i> by Don Box is very insightful for learning COM.

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

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