QLibrary is not loading DLL

Question

I want to load DLL in a C++ program and create function pointers. To avoid any confusion, I am providing the absolute path of the DLL. But still, the DLL is not loaded.

My Code:

void CallFunctionPointers()
{
    QString strMsg;
    QString strLibPath("D:\\dll\\AtmoRemote.dll");

    QLibrary* m_p_lib = new QLibrary();
    m_p_lib->setFileName(strLibPath);

    if (!m_p_lib->load())
    {
        strMsg = QString("Could not load %1").arg(strLibPath); //<<<<-----------PROGRAM ALWAYS ENTERS HERE
    }
    else
    {
        strMsg = QString("Successfully loaded: %1").arg(strLibPath); 
    }
}

score 3 · Accepted Answer · answered Sep 16 '19 at 20:48

3

There may be many reasons, impossible to diagnose with the details provided here.

For instance: the process using Qt is 64 bits and the DLL is 32 bits. Or vice-versa. Another one: the DLL depends on other DLLs not available by QLibrary. My suggestion for you: use dependency walker or a similar utility to diagnose these issues.

answered Sep 16 '19 at 20:48

Former contributor

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Ok, I used the dependency walker any found out that the DLL is in x32 configuration and that's why did not load in my program. – skm Sep 17 '19 at 07:59

score 2 · Answer 2 · edited Jun 20 '20 at 09:12

2

Check for the error.

QString QLibrary::errorString() const

Returns a text string with the description of the last error that occurred. Currently, errorString will only be set if load(), unload() or resolve() for some reason fails.

edited Jun 20 '20 at 09:12

Community

1
1

answered Sep 16 '19 at 20:00

ypnos

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`errorString()` returns `cannot load library D:\dll\Remote.dll`...not much helpful. – skm Sep 16 '19 at 20:21
Ain't that great – ypnos Sep 16 '19 at 21:29

QLibrary is not loading DLL

2 Answers2