How to use a variable inside a _T wrapper ? (MFC Dialog app C++)

July 12, 2022

I want to generate 17 service names in the List Control. How can i use a formatted string variable inside a _T wrapper ?

// TODO: Add extra initialization here

#define MAX_VALUE 17

    int numberOfService = 0;
    CString StringServiceName;

    StringServiceName.Format(_T("Sense Counter %d"), numberOfService);

    for (numberOfService; numberOfService < MAX_VALUE; numberOfService++) {

        int nIndex = m_List.InsertItem(0, _T("")); //This variable i want to use in a _T wrapper - StringServiceName.Format(_T("Sense Counter %d"), numberOfService)

    }

    m_List.InsertColumn(0, _T("Názov služby"), LVCFMT_LEFT,150);
    m_List.InsertColumn(1, _T("Status"), LVCFMT_LEFT, 90);
    m_List.InsertColumn(2, _T(""), LVCFMT_LEFT, 90);

    int nIndex = m_List.InsertItem(0, _T("Sense Counter 1"));
    m_List.SetItemText(nIndex, 1, _T("Running"));
    m_List.SetItemText(nIndex, 2, _T("✓"));

    nIndex = m_List.InsertItem(1, _T("Sense Counter 2"));
    m_List.SetItemText(nIndex, 1, _T("Stopped"));
    m_List.SetItemText(nIndex, 2, _T("✓"));

>Solution :

You can’t – _T is just a macro to generate narrow or wide string constants, depending on whether you’re compiling for Unicode or not.

I’m not over-familiar with CString, but perhaps you meant this:

for (numberOfService; numberOfService < MAX_VALUE; numberOfService++) {
    StringServiceName.Format(_T("Sense Counter %d"), numberOfService)
    int nIndex = m_List.InsertItem(0, (LPCTSTR) StringServiceName);
}

(The cast may not be necessary here, although Microsoft recommends it – try without.)