'CComPtr' : use of class template requires template argum

[sunijam]

Hello folks,
I am newbie to ATL/COM programming!!!! I am trying to add a COM dll in Visual C++ for PocketPC 2002. So i took a simple hello world program and tried to instantiate an object of one of the interfaces in the dll. I am not able to compile. Looks like I am getting an error in trying to initialize using CComPtr. Would really appreciate your help.!!!!

I have attached the code here and also the compile errors. I am hard pressed with time to finish this. I am not able to proceed further. Would really appreciate any help you can give.

I have also included atlbase.h
CComPtr <IReader> pMobileObj;
// creating a MobileObj object
HRESULT hr =pMobileObj.CoCreateInstance(CLSID_Reader);

Compile errors:
Test.cpp
C:\SMM6.4\POCKETPC\VC++\Test\Test.cpp(159) : error C2065: 'IReader' : undeclared identifier
C:\SMM6.4\POCKETPC\VC++\Test\Test.cpp(159) : error C2955: 'CComPtr' : use of class template requires template argument list
C:\Windows CE Tools\wce300\Pocket PC 2002\atl\include\atlbase.h(674) : see declaration of 'CComPtr'
C:\SMM6.4\POCKETPC\VC++\Test\Test.cpp(159) : error C2133: 'pMobileObj' : unknown size
C:\SMM6.4\POCKETPC\VC++\Test\Test.cpp(159) : error C2512: 'CComPtr' : no appropriate default constructor available
C:\SMM6.4\POCKETPC\VC++\Test\Test.cpp(159) : error C2262: 'pMobileObj' : cannot be destroyed
C:\SMM6.4\POCKETPC\VC++\Test\Test.cpp(161) : error C2065: 'CLSID_Reader' : undeclared identifier

-sunijam

 

[cdraycott]

sunijam,

Are you using Embedded Visual C++? If so then does this help at all?

http://www.pocketpcdn.com/articles/_com_issue_error.html

 

[sunijam]

Thank you so much cdraycott. That helped me understand why I am getting this error. But I still seem to get a serious of these errors. I am not able to understand why. I think I am missing some dll's or libraries.
Have you come across this situation?

This is the serious of errors:
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(49) : error C2065: 'IConverterPtr' : undeclared identifier
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(49) : error C2146: syntax error : missing ';' before identifier 'cnv'
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(49) : error C2065: 'cnv' : undeclared identifier
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(50) : error C2065: 'gt' : undeclared identifier
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(50) : error C2113: pointer can only be subtracted from another pointer
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(50) : error C2065: 'IntToString' : undeclared identifier
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(170) : error C2065: 'ITagReader' : undeclared identifier
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(170) : error C2955: 'CComPtr' : use of class template requires template argument list
C:\Windows CE Tools\wce300\Pocket PC 2002\atl\include\atlbase.h(674) : see declaration of 'CComPtr'
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(170) : error C2133: 'pMobileReader' : unknown size
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(170) : error C2512: 'CComPtr' : no appropriate default constructor available
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(170) : error C2262: 'pMobileReader' : cannot be destroyed
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(172) : error C2065: 'CLSID_TagReader' : undeclared identifier

 

[cdraycott]

sunijam,

i would need to see source code here. It looks like there may be some syntactical errors here as well as errors relating to CComPtr.

 

[sunijam]

Hello cdraycott,
here is the source code.

This is the code I added in StdAfx.h
#define ST_IGNORE_COM_EXCEPTIONS
#include "STUtil.h"

void _com_issue_error(HRESULT hr);
void _com_issue_errorex(HRESULT hr, IUnknown* pUnkn, REFIID riid);
#import "c:\Windows\SaviReader.dll" named_guids, no_namespace, raw_interfaces_only

This is what I have added in main file.cpp.
/*************************************************************
// I get an error in error C2065: 'IConverterPtr' : undeclared identifier after adding #define ST_IGNORE_COM_EXCEPTIONS.
/**************************************************************

int WINAPI WinMain( HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPTSTR lpCmdLine,
int nCmdShow)
{
MSG msg;
HACCEL hAccelTable;


IConverterPtr cnv(_T("Test.Converter"));
_bstr_t str = cnv-&gt;IntToString(46);
// Perform application initialization:
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
}

hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_TEST);

// Main message loop:
while (GetMessage(&msg, NULL, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}

return msg.wParam;
}


/**************************************************************
// I get the following error from this piece of code.
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(170) : error C2065: 'ITagReader' : undeclared identifier
C:\SMM6.4\PocketPC\VC++\Test\Test.cpp(170) : error C2955: 'CComPtr' : use of class template requires template argument list
C:\Windows CE Tools\wce300\Pocket PC 2002\atl\include\atlbase.h(674) : see declaration of 'CComPtr'
/****************************************************************

void DoMobileReader()
{

CComPtr <ITagReader> pMobileReader;
// creating a MobileReader object
HRESULT hr = pMobileReader.CoCreateInstance(CLSID_TagReader);
if(SUCCEEDED(hr))
{
printf(" successful in object creation\n");
}
}

void _com_issue_error(HRESULT hr)
{
//Insert a custom implementation, such as the following.
TRACE( _T("Caught unhandled COM exception!\n") );
}

void _com_issue_errorex(HRESULT hr, IUnknown* pUnkn, REFIID riid)
{
//Insert a custom implementation, such as the following.
TRACE( _T("Caught unhandled COM exception!\n") );
}