CImageList / CComboBoxEx - what's wrong?

[Lost User]

Hi I'm using this code to insert items into my CComboBoxEx with icons:

BOOL CConfigDlg::OnInitDialog()
{
CDialog::OnInitDialog();

m\_Images.Create(IDB\_ICONS, 16, 1, RGB (0, 128, 128));
m\_ctlCombo.SetImageList(&m\_Images);

for(int j=0; j<8; j++)
{
CString string;
string.Format (\_T ("Item %d"), j);

COMBOBOXEXITEM cbei;
cbei.mask = CBEIF\_IMAGE | CBEIF\_SELECTEDIMAGE | CBEIF\_TEXT;
cbei.iItem = j;
cbei.pszText = (LPTSTR) (LPCTSTR)string;
cbei.iImage = j;
cbei.iSelectedImage = j;

m\_ctlCombo.InsertItem(&cbei);
}

return TRUE;

}

But for some reason my Combobox remains empty. Does anybody know why? thanks in advance Greg

[Mike Upton]

That code looks correct to me, but there are a couple of other things I can think of:

• Is the m_ctlCombo variable hooked up to the actual control properly? Is there a DDX_Control call for it in the CConfigDlg::DoDataExchange method?
• Is the control on the dialog resource actually a ComboBoxEx, or is it only a standard ComboBox?

As a very minor point, I don't like the (LPTSTR)(LPCTSTR)string cast, because I tend to think it's bad practice to cast away the const. How about:

cbei.pszText=string.GetBuffer(0);
...
m_ctlCombo.InsertItem(&cbei);
string.ReleaseBuffer();

---

"We are the knights who say Ni" (The Knights Who Say Ni)

[Lost User]

Mike Upton wrote: Is the m_ctlCombo variable hooked up to the actual control properly? Is there a DDX_Control call for it in the CConfigDlg::DoDataExchange method?

void CConfigDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CConfigDlg)
DDX_Control(pDX, IDC_COMBO, m_ctlCombo);
...

Mike Upton wrote: Is the control on the dialog resource actually a ComboBoxEx, or is it only a standard ComboBox?

class CConfigDlg : public CDialog
{
public:
CConfigDlg(CWnd* pParent = NULL);
//{{AFX_DATA(CConfigDlg)
enum { IDD = IDD_CONFIG };
CComboBoxEx m_ctlCombo;

I don't know what's wrong :confused:

[DanielP]

What does InsertItem() return? suggestions: 1. you don't need invoke GetBuffer(0). you can use just Lock() and UnLock(). 2. Clear COMBOBOXEXITEM before using by ZeroMemory(). 3. set cchTextMax in COMBOBOXEXITEM

[Mike Upton]

Gregor S. wrote: _Mike Upton wrote: Is the control on the dialog resource actually a ComboBoxEx, or is it only a standard ComboBox?

class CConfigDlg : public CDialog
{
public:
CConfigDlg(CWnd* pParent = NULL);
//{{AFX_DATA(CConfigDlg)
enum { IDD = IDD_CONFIG };
CComboBoxEx m_ctlCombo;_
Sorry, that's not what I meant. What I meant was, did you insert the control into the dialog resource (in the dialog resource editor) as a standard combo box or an extended combobox? I've just created a test dialog based project using the AppWizard, added an extended combo box to the dialog (and used the wizard to add a control variable for it), added a bitmap to use for the images and an image list member in the dialog, then copied and pasted your code into the OnInitDialog method and everything works perfectly.

---

"We are the knights who say Ni" (The Knights Who Say Ni)

[Lost User]

Oh, I didn't see the icon for the extended combobox in my dialog resource editor toolbar. I replaced my old comboboxes with the new ones an now everything works fine :) Thank you very much for your help! :rose: