C / C++ / MFC

////////////////////////////////////////////////////////////////
// OnInitDialog

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

	CString strItemName;

        // Insert some dummy items into the tree...
	for(int i = 0; i < 20; i++){

		strItemName.Format(_T("Item%d"), i);
		HTREEITEM hItem = m_Tree.InsertItem(strItemName);
		ASSERT(NULL != hItem);

                // Set the check for the new item.
		m_Tree.SetCheck(hItem, TRUE);
	}

	return TRUE;
}

m_Tree.ModifyStyle(0, TVS_CHECKBOXES);
for (...)
{
m_Tree.InsertItem(...);
m_Tree.SetCheck(...);
}