ATL / WTL / STL

Re: Error while creating object using CreateInstance()

6-Mar-08 0:31

//Main.h
__interface IFileIO : IDispatch
{
[id(1), helpstring("method GetFile")] HRESULT GetFile();
[id(2), helpstring("method getDirectory")] HRESULT GetDirectory();
};

class ATL_NO_VTABLE EDCService :public IFileIO
{
public:
EDCService()
{
}
DECLARE_PROTECT_FINAL_CONSTRUCT()
HRESULT FinalConstruct()
{
return S_OK;
}

void FinalRelease()
{
}

public:

STDMETHOD(GetFile);
STDMETHOD(GetDirectory);
}

Hi friends ...

STDMETHOD(GetFile);
STDMETHOD(GetDirectory); these two methods definitions are written main.cpp

i doing so many try's to solve this prob..first i create instance of EDCService.like

EDCService edcobj;

then i create instance of EDCService like

edcobj.CreateInstance(); but showing..

When i compile this code i get the follwing errors i dont know how was solve it

error C2039: 'CreateInstance' : is not a member of 'EDCService'

error C2259: 'EDCService' : cannot instantiate abstract class

Please tell me how to solve this problem ..

Nathan Holt at EMOM6-Mar-08 4:42

Nathan Holt at EMOM

6-Mar-08 4:42

Sakthi_Vel wrote:
then i create instance of EDCService like

edcobj.CreateInstance(); but showing..

When i compile this code i get the follwing errors i dont know how was solve it

error C2039: 'CreateInstance' : is not a member of 'EDCService'

You aren't supposed to create an instance that way. If you are inside your program, you could use CComObject<edcservice>::CreateInstance. To create it from a client, you would normally assign a class ID to EDCService and the use CoCreateInstance.

Sakthi_Vel wrote:
error C2259: 'EDCService' : cannot instantiate abstract class

IDispatch has four pure virtual methods that you can implement by deriving EDCService from IDispatchImpl. IDispatch derives from IUnknown which has three more methods, which are implemented in CComObject. Also you need an interface map for EDCService so that CComObject::QueryInterface can work correctly.

Sakthi_Vel wrote:
//Main.h
__interface IFileIO : IDispatch
{
[id(1), helpstring("method GetFile")] HRESULT GetFile();
[id(2), helpstring("method getDirectory")] HRESULT GetDirectory();
};

This looks like attributed ATL. You really don't want to use it. Attribute support for standard C++ is much weaker than for .net, and I've found that (at least with VS2003) that it has an extreme problem with interface dependancies, because the generated .idl file neither forward declares types, nor attempts to put them in an order which wouldn't need it. To do anything significant with ATL, you'll need to learn IDL.

Nathan

Bug in atlhost.h

imagiro29-Feb-08 0:51

imagiro

29-Feb-08 0:51

I don't know where to report this bug, so may be this is the right place...
If you set an IDocHostUIHandlerDispatch-interface the FilterDataObject-Method of CAxHostWindow does NOT query the IDataObject-interface from the returned IUnknown, instead it calls QueryInterface on it self:

if (m_spIDocHostUIHandlerDispatch != NULL)
{
	CComPtr<iunknown> spUnk;
	hr = m_spIDocHostUIHandlerDispatch->FilterDataObject(pDO, &spUnk);
	if (spUnk)
		hr = QueryInterface(__uuidof(IDataObject), (void**)ppDORet);    // self!!
	if (FAILED(hr) || *ppDORet == NULL)
		hr = S_FALSE;
}
</iunknown>

So the line

hr = QueryInterface(__uuidof(IDataObject), (void**)ppDORet);

should be more like:

hr = spUnk->QueryInterface(__uuidof(IDataObject), (void**)ppDORet);

Does anyone know where to report this bug?

Greetings,
imagiro

Re: Bug in atlhost.h

Michael Dunn29-Feb-08 9:29

Michael Dunn

29-Feb-08 9:29

connect.microsoft.com[^] is the place to report bugs, or post in a MS support forum.

--Mike--
Visual C++ MVP Cool | :cool:

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"That's what's great about doing user interface work. No matter what you do, people will say that what you did was idiotic." -- Raymond Chen

Reporting Bugs

imagiro6-Mar-08 21:57

imagiro

6-Mar-08 21:57

Thanks Mike. Looks like reporting bugs is sometimes harder than finding them Wink | ;)

Getting element id on click event from web browser in ATL

ashish@indianic27-Feb-08 20:28

ashish@indianic

27-Feb-08 20:28

Hi All,

I have developed the project in ATL in which I am getting events from the browser window through Invoke() function of the IDispatch interface.

And my question is that I want to get Mouse Click event with the element id on which event has been fired.How can I do that?

I tried below code to do the same but I m not getting success.

<br />
<br />
STDMETHODIMP CSimpleTab::Invoke(DISPID dispIdMember, REFIID riid, LCID lcid, WORD wFlags,<br />
                                    DISPPARAMS* pDispParams, VARIANT* pVarResult,<br />
                                    EXCEPINFO* pExcepInfo, UINT* puArgErr)<br />
{<br />
      switch (dispIdMember)<br />
      {<br />
          case DISPID_HTMLELEMENTEVENTS2_ONMOUSEDOWN:<br />
          {<br />
              CComVariant dis_event;<br />
			  dis_event = (CSimpleTab *)(this);<br />
			  <br />
			  IDispatch *lpDispatch = pVarResult->pdispVal;<br />
			  IHTMLEventObj * eventObj;<br />
			  HRESULT hr = lpDispatch->QueryInterface(IID_IHTMLEventObj,(void **)&eventObj);<br />
<br />
			  IHTMLElement * element;<br />
			  eventObj->get_srcElement(&element);<br />
          }<br />
      }<br />
}<br />

in above code I m getting null in to the pVarResult->pdispVal parameter.
Do you have any idea why does this happen?
Thanks in Advance.

Ashish Bhatt,
Indianic,Ahmedabad.

How to use messagebox in ATL

KASR126-Feb-08 21:41

26-Feb-08 21:41

I am new to ATL. How to display a message box in ATL projects?

ThatsAlok26-Feb-08 21:59

ThatsAlok

26-Feb-08 21:59

Sakthi_Vel wrote:
I am new to ATL. How to display a message box in ATL projects?

::MessageBox(NULL,_T(""),_T(""),MB_OK); same like any win32 project

"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/codeProject$$>

prasad_som5-Mar-08 4:57

prasad_som

5-Mar-08 4:57

As said by Alok , you can use win32 api's.

Or use CWindow::MessageBox[^].

dfz6-Mar-08 0:11

dfz

6-Mar-08 0:11

Another WinApi wrapper function AtlMessageBox

KASR16-Mar-08 0:14

6-Mar-08 0:14

Thanks to all.
Indeed more than i need Poke tongue | ;-P

How to handle strings in ATL.

Hamid_RT14-Apr-08 21:53

Hamid_RT

14-Apr-08 21:53

If you are new to ATL see http://msdn2.microsoft.com/en-us/library/599w5e7x(VS.80).aspx[^].

KASR126-Feb-08 19:23

26-Feb-08 19:23

How to declare/handle strings in ATL?

MANISH RASTOGI26-Feb-08 21:09

MANISH RASTOGI

26-Feb-08 21:09

Simple As you do in C++
char szBuffer[100];
Or
TCHAR szBuffer[100];

ThatsAlok26-Feb-08 21:58

ThatsAlok

26-Feb-08 21:58

Sakthi_Vel wrote:
How to declare/handle strings in ATL?

include atlstr.h , it provide you CString class!

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

KASR12-Mar-08 19:02

2-Mar-08 19:02

Yes it works. Thanks.

ThatsAlok2-Mar-08 19:26

ThatsAlok

2-Mar-08 19:26

Sakthi_Vel wrote:
Thanks.

my pleasure

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

Nemanja Trifunovic5-Mar-08 3:50

Nemanja Trifunovic

5-Mar-08 3:50

Another option is to use ATL's CComBSTR[^] class.

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