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You can not. There is a rule(standard) of COM which states that you can only have one dispatch interface in the COM object. The reason for that is that late binding clients(VBS) use QueryInterface(IDispatch)/Invoke(methodID) for everything.
1. You can try to implement IMIDraw as separate object and expose it through a method of IPlot2D.
2. If they are polymorphic you can try to derive IMIDraw from IPlot2D, this way you can expose both interfaces and not violate the rule.
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In addition to the previous reply, you can choose to implement your own IDispatch which will take care of all the methods for both interfaces. However, it is not the best solution, and you will have to take care to name clashes.
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Thank you very much, solon.
I put a new method Plot0() in IPlot2D, and Plot() is launch there. It's OK.
Thanks again.
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this is not exactly what I meant – I was talking about a custom implementation of IDispatch, where you redirect the Invoke call to the appropriate IDispatch implementation.
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Hi again,
I am interested in writing a com/alt/ole object/server. Oh hell, I don't know what I want to write. 
What I want is an object that you can insert into word or Autocad, that displays information with a customizable view. The object is to be created by a seperate desktop app, that embeds the data. I have played around with VC++ MFC AppWizard to create an ActiveX full server. This is kind of what I want. The UI that I envisioned was just a simple dialog box, not the inplace frame thingy that you get with MFC. Also, it is possible that this object will eventually wind up on the web so I was hoping to avoid MFC.
I have played around a little with an ATL full control. Can I register the control somehow so that it is avalible from the insert object menu in word? If not a control, ATL must have a template to serve my needs.
Maybe someone could point me in the right direction as far as what technology I should be studying for the desired outcome. COM is such a big topic !!!
Thanks,
Paul
ps. Think I need some 
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The task your planning is very interesting, but could be very difficult. One item on your list is easy, use ATL wizard to create full control, and make sure insertable is checked. As for the rest, you might want to go ALT/WTL, however only ATL part is well documented (check out MSDN samples/tutorials). The only decent resource for WTL I know of is ... this site. Check out the collection of the samples & libraries at http://www.codeproject.com/wtl. I am guessing your are new to COM (forgive me if I am wrong), so check out "http://www.amazon.com/exec/obidos/tg/detail/-/0201634465/qid=1041259989/sr=8-2/ref=sr_8_2/104-4316939-3607113?v=glance&s=books&n=507846" - it might help you.
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Paul Silvernail wrote:
Can I register the control somehow so that it is avalible from the insert object menu in word?
There's a checkbox for this in the ATL wizard IIRC.
--
Only in a world this sh*tty could you even try to say these were innocent people and keep a straight face.
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I'm using a COM Object that have a ConnectionPoint (event) that looks like this:
void RecognitionStoppedEvent(
RecognitionType RType,
ReasonType Reason,
IKVSet* RecResult);
Then I use a class that inherits from IDispatchImpl to receive the event.
Everything works fine, except I cant use the IKVSet*, I get an exception and the function just exists 
An IKVset's IDL looks like this: interface IKVSet : IDispatch {code....}
I use this "definition" in my implementation of the event, but I'm not exactly sure about the VT_DISPATCH, is this the right varenum?
static _ATL_FUNC_INFO OnRecognitionStoppedEventInfo = {CC_STDCALL, VT_EMPTY, 3, {VT_I4, VT_I4, VT_DISPATCH}};
- Anders
Money talks, but all mine ever says is "Goodbye!"
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VT_DISPATCH corresponds to IDispatch* so that is correct. The event probably sends an IDispatch*, not an IKVSet*, so I'd first suggest QI'ing the pointer for IKVSet
--Mike--
If it doesn't move and it should: WD-40. If it moves and it shouldn't: duct tape.
1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm
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Thanks a lot Mike, it did the trick 
Why did'nt I think of that my self 
- Anders
Money talks, but all mine ever says is "Goodbye!"
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Don't worry! There are only VT_DISPATCH and VT_UNKNOWN to mark interfaces. VT_DISPATCH is used for interfaces which derived from IDispatch prior to IUnknown.
Try to QueryInterface of IID_IKVSet on your pointer and check the HRESULT returned.
Or check __stdcall keyword which must be presented for "RecognitionStoppedEvent" function.
With best wishes,
Vita
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Sould this work in the ATL class CAxDialogImpl?
LRESULT OnInitDialog(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
// IDC_NAME is a textbox
::SetDlgItemText(::GetActiveWindow(), IDC_NAME, _T("Wahoo!!!");
return 1; // Let the system set the focus
}
or should it be done differently?
Thanks,
Paul
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Use CWindow::SetDlgItemText() instead:
SetDlgItemText ( IDC_NAME, _T("Wahoo!!") );
--Mike--
If it doesn't move and it should: WD-40. If it moves and it shouldn't: duct tape.
1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm
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Hello All,
In VS.NET General project property page, there is this property
"Use of ATL".
What really is the meaning of this? Even in WTL project generated
with the wizard, this property is set to "Not Using ATL".
This is what the documentation/help has to say:
Use of ATL
Specifies whether the ATL project will statically or dynamically link to the ATL .DLL.
If you specify anything other than Not Using ATL, a define of some kind will be added
to the compiler's Command Line property page.
What is the "define of some kind" that the documentation is refering to here?
Best regards,
Paul.
Jesus Christ is LOVE! Please tell somebody.
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_ATL_DLL - is one of them. The second I do not know.
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Hi
Is QueryInterface call AddRef() ?
STDMETHODIMP CPatternGenerator::GetLayout(long lIndex, ILayout ** pVal)
{
// TODO: Add your implementation code here
if (lIndex >=0 && lIndex < m_vLayoutList.size()){
m_vLayoutList[lIndex]->QueryInterface(IID_ILayout, (void**) pVal);
m_vLayoutList[lIndex]->AddRef(); // Is this statement required.
return S_OK;
}
return E_INVALIDARG;
}
My understanding is that QueryInterface has already called AddRef so we dont need it. Am i correct?
Thanks
Qur
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Yes, the returned interface has incremented the reference count prior to being returned to you.
Tim Smith
I'm going to patent thought. I have yet to see any prior art.
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Hi
I am new in atl com and little confuse about the reference management.
Here is the code:
typedef stack <CComObject <CLayout> *> LAYOUTSTACK;
typedef vector <CComObject <CLayout> *> LAYOUTVECTOR;
CComObject <clayout> * oLayout;
LAYOUTSTACK sLayout;
sLayout.push (m_opLayout); //where m_opLayout is private memeber
oLayout = sLayout.top();
oLayout->AddRef(); //question: this statement is required or not and why?
m_vLayoutList.push_back(oLayout); //private member of type LAYOUTVECTOR
sLayout.pop();
On general do we need to call AddRef if pointer assignment is done for CComObject <>.
Thanks
Qur
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qur wrote:
do we need to call AddRef if pointer assignment is done for CComObject.
CComObject is not a smart pointer class, so any time you create a new reference to the underlying object, you need to AddRef() it.
--Mike--
If it doesn't move and it should: WD-40. If it moves and it shouldn't: duct tape.
1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm
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What is the good way to create the coclass object that can take care of reference count.
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Michael Dunn wrote:
CComObject is not a smart pointer class, so any time you create a new reference to the underlying object, you need to AddRef() it.
Ok, not know hardly anything about COM I have a question off this answer. I assume that CComObject is an already wrapped class/object? Otherwise wouldn't you call an AddRef(); function inside your constructor to increment the reference counting? I suppose a more generalized answer to my question would be for me to read more about COM. In due time I suppose.
Nick Parker
You see the Standards change. - Fellow co-worker
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ATL abstracts IUnknown implementation in three classes : CComObject / CComAggObject and CComPolyObject - CComObject provides the IUnknown implementation for non-aggregated objects.
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I have to question:
1- If I chose "yes" in aggregation section of ATL Object Wizard then should a create the coclass object using CComAggObject or CComObject?
2- Do same reference counting rules apply when creating coclass object through CComObject as with interface pointers?
Thanx in advance.
qur
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If you choose "yes" for aggregation then your class can run either standalone or aggregated, so you can use both CComObject or CComAggObject ( depending on your needs). And yes , you will have to take care of the object lifetime, addref-ing and releasing properly any object created by CComObject. However, if you just want to create and use an object inside a function you can use CComObjectStack - it doesn't perform reference counting.
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Can I supress the "look if item is still there", when I insert an item into a map?
(I already verified that the item is not there, and want to save the overhead)
If I could find a souvenir / just to prove the world was here [sighist]
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