Creation of a CRuntimeClass* using FromName()

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Good day,

I am trying to create a CRuntimeClass pointer using a string with the name of the Class, CMyClass, as per below

C#

CRuntimeClass * pClass = CRuntimeClass::FromName(L"CMyClass");

CMyClass has been already declared as DYNCREATE with base class CRecordView.

No matter all efforts spent, specific pointer returns as NULL.

On debugging, i have noticed that in the following code:

QUOTE

C#

CRuntimeClass* PASCAL CRuntimeClass::FromName(LPCSTR lpszClassName)
{
    CRuntimeClass* pClass=NULL;

    ENSURE(lpszClassName);

    // search app specific classes
    AFX_MODULE_STATE* pModuleState = AfxGetModuleState();
    AfxLockGlobals(CRIT_RUNTIMECLASSLIST);
    for (pClass = pModuleState->m_classList; pClass != NULL;
        pClass = pClass->m_pNextClass)
    {
        if (lstrcmpA(lpszClassName, pClass->m_lpszClassName) == 0)
        {
            AfxUnlockGlobals(CRIT_RUNTIMECLASSLIST);
            return pClass;
        }
    }

UNQUOTE

variable m_classList do NOT contain my CMyClass.

Any help is much appreciated.

Posted 21-Oct-15 15:07pm

Dimitrios Fountoukidis

Updated 24-Jul-23 21:41pm

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Richard MacCutchan · Answer 1 · 2015-10-21T22:14:00

Solution 1

You are passing a Unicode string to a function that requires ASCII. Either change your constant or rebuild your application for Unicode.

Posted 21-Oct-15 22:14pm

Richard MacCutchan

Comments

Dimitrios Fountoukidis 22-Oct-15 5:48am

Thanks but as per below, didn't work

CStringA strClass("CMyClass");
CRuntimeClass * pClass = CRuntimeClass::FromName(strClass);

Still returns NULL

Also as per MS: FromName accepts:

static CRuntimeClass* PASCAL FromName(
LPCSTR lpszClassName
);
static CRuntimeClass* PASCAL FromName(
LPCWSTR lpszClassName
);

thanks again

Richard MacCutchan 22-Oct-15 5:51am

You need to ensure all your code is Unicode or all ASCII. And do not use the A or W suffixes on class and function names, it just confuses everything.

Dimitrios Fountoukidis 22-Oct-15 6:14am

I have also tried the following

CRuntimeClass* point = RUNTIME_CLASS(CMyClass);
CRuntimeClass* pClass = CRuntimeClass::FromName(point->m_lpszClassName);

Although point was successfully created but pClass returned as NULL.

Do i need to declare or include any library in my code?

Richard MacCutchan 22-Oct-15 6:43am

I do not use MFC so cannot test a sample for you.

uweph · Answer 2 · 2023-07-24T21:16:00

Solution 2

DECLARE_DYCREATE is not enough. You need DECLARE_SERIAL

Only then your class is added to ModuleState->m_classList.

Posted 24-Jul-23 21:16pm

uweph

Updated 24-Jul-23 21:43pm

Comments

OriginalGriff 25-Jul-23 3:44am

While I applaud your urge to help people, it's a good idea to stick to new questions, rather than 8 year old ones. After that amount of time, it's unlikely that the original poster is at all interested in the problem any more!
Answering old questions can be seen as rep-point hunting, which is a form of site abuse. The more trigger happy amongst us will start the process of banning you from the site if you aren't careful. Stick to new questions and you'll be fine.