'How can I use UpdateData func in controlling function (UINT) in MFC App?

I'm creating a multi-threading program with MFC using controlling function is UINT. Now I want to update GUI using UpdateData(FALSE), but visual studio 2022 say that

- a nonstatic member reference must be relative to a specific object
- CWnd::UpdateData': illegal call of non-static member function

Here is my UINT code:

UINT MyThreadProc(LPVOID Param) {
CFolderPickerDialog m_dlg;
   m_dlg.m_ofn.lpstrTitle = _T("Select Folder To Scan");
   m_dlg.m_ofn.lpstrInitialDir = _T("C:\\");
   if (m_dlg.DoModal() == IDOK) {
       m_Path = m_dlg.GetPathName();   
       m_Path += _T("\\");
       CWnd::UpdateData(FALSE);
   }
}

void CMultithreadDlg::OnBnClickedButtonBrowse(){
   AfxBeginThread(MyThreadProc,this);
   UpdateData(FALSE);
   GetDlgItem(IDC_BUTTON_Browse)->EnableWindow(FALSE);
   GetDlgItem(IDC_EDIT_PATH)->EnableWindow(FALSE);
}

How can I fix this, thanks

c++multithreadinguser-interfacemfcstatic-methods


Solution 1:[1]

Let's consider that CFolderPickerDialog was just an example, and get back to the core of the question.

Your compiler told you that the way you call UpdateData()

CWnd::UpdateData(FALSE);

is specifying a call to a static function UpdateData() of the class CWnd, and that doesn't exists.

You need to call that function on a specific instance of CWnd. Luckily - you have it! You pass your this pointer to that thread function:

AfxBeginThread(MyThreadProc,this);

So inside that function you can safely cast LPVOID Param (that you are not using currently) to a pointer to CWnd or CMultithreadDlg. Then you will be able to call any non-static functions via that pointer.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Vlad Feinstein

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