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How to create a directory listing in a single-selection ListBox

  • Article

This topic demonstrates how to use a single-selection list box to display and access the contents of a directory. The single-selection list box is the default list box type. A user can only select one item at a time from a single-selection list box.

The C++ code example in this topic enables a user to view a list of files in the current directory, select a file from the list, and delete it.

What you need to know

Technologies

Prerequisites

  • C/C++
  • Windows User Interface Programming

Instructions

The directory listing application must perform the following list box related tasks:

  • Initialize the list box.
  • Retrieve the user's selection from the list box.
  • Remove the file name from the list box after the selected file has been deleted.

In the following C++ code example, the dialog box procedure initializes the single-selection list box (IDC_FILELIST) by using the DlgDirList function to fill the list box with the names of all the files in the current directory. When the user selects a file and chooses the Delete button, the DlgDirSelectEx function retrieves the name of the selected file. The code deletes the file by using the DeleteFile function and updates the directory list box by sending the LB_DELETESTRING message.

INT_PTR CALLBACK DlgDelFileProc(HWND hDlg, UINT message, 
        UINT wParam, LONG lParam) 
{ 
    PTSTR pszCurDir; 
    PTSTR pszFileToDelete; 
    int iLBItem; 
    int cStringsRemaining; 
    int iRet; 
    TCHAR achBuffer[MAX_PATH]; 
    TCHAR achTemp[MAX_PATH]; 
    BOOL fResult;     
 
    switch (message) 
    { 
        case WM_INITDIALOG: 
 
           // Initialize the list box by filling it with files from 
           // the current directory. 
           pszCurDir = achBuffer; 
           GetCurrentDirectory(MAX_PATH, pszCurDir); 
           DlgDirList(hDlg, pszCurDir, IDC_FILELIST, IDS_PATHTOFILL, 0); 
           SetFocus(GetDlgItem(hDlg, IDC_FILELIST)); 
           return FALSE; 
 
        case WM_COMMAND: 
 
            switch (LOWORD(wParam)) 
            { 
                case IDOK: 
 
                    // When the user presses the DEL (IDOK) button, 
                    // first retrieve the selected file. 
                    pszFileToDelete = achBuffer; 
                    DlgDirSelectEx(hDlg, pszFileToDelete, MAX_PATH, 
                        IDC_FILELIST); 

                    // Make sure the user really wants to delete the file.
                    achTemp[MAX_PATH];
                    StringCbPrintf (achTemp, ARRAYSIZE(achTemp),  
                            TEXT("Are you sure you want to delete %s?"), 
                            pszFileToDelete);
                    iRet = MessageBox(hDlg, achTemp, L"Deleting Files", 
                        MB_YESNO | MB_ICONEXCLAMATION);
                    if (iRet == IDNO)
                        return TRUE;;

                    // Delete the file.
                    fResult = DeleteFile(pszFileToDelete); 
                    if (!fResult) 
                    { 
                        MessageBox(hDlg, L"Could not delete file.", 
                            NULL, MB_OK); 
                    } 
                    else // Remove the filename from the list box.
                    { 
                        // Get the selected item.
                        iLBItem = SendMessage(GetDlgItem(hDlg, IDC_FILELIST), 
                            LB_GETCURSEL, 0, 0); 
 
                        // Delete the selected item.
                        cStringsRemaining = SendMessage(GetDlgItem(hDlg, IDC_FILELIST), 
                            LB_DELETESTRING, iLBItem, 0); 
 
                        // If this is not the last item, set the selection to 
                        // the item immediately following the one just deleted.
                        // Otherwise, set the selection to the last item.
                         if (cStringsRemaining > iLBItem) 
                        { 
                            SendMessage(GetDlgItem(hDlg, IDC_FILELIST), 
                                LB_SETCURSEL, iLBItem, 0); 
                        } 
                        else 
                        { 
                            SendMessage(GetDlgItem(hDlg, IDC_FILELIST), 
                                LB_SETCURSEL, cStringsRemaining, 0); 
                        } 
                    } 
                    return TRUE; 
 
                case IDCANCEL: 
 
                    // Destroy the dialog box. 
                     EndDialog(hDlg, TRUE); 
                    return TRUE; 
 
                default: 
                    return FALSE; 
            } 
 
        default: 
            return FALSE; 
    } 
}

List Box Control Reference

About List Boxes

Using List Boxes