Using Drop-Down Buttons in a Toolbar Control
In addition to standard push buttons, a toolbar can also have drop-down buttons. A drop-down button is usually indicated by the presence of an attached down arrow.
Hinweis
The attached down arrow will appear only if the TBSTYLE_EX_DRAWDARROWS extended style has been set.
When the user clicks on this arrow (or the button itself, if no arrow is present), a TBN_DROPDOWN notification message is sent to the parent of the toolbar control. You can then handle this notification and display a pop-up menu; similar to the behavior of Internet Explorer.
The following procedure illustrates how to implement a drop-down toolbar button with a pop-up menu:
To implement a drop-down button
Once your CToolBarCtrl object has been created, set the TBSTYLE_EX_DRAWDDARROWS style, using the following code:
m_ToolBarCtrl.SetExtendedStyle(TBSTYLE_EX_DRAWDDARROWS);
Set the TBSTYLE_DROPDOWN style for any new (InsertButton or AddButtons) or existing (SetButtonInfo) buttons that will be drop-down buttons. The following example demonstrates modifying an existing button in a CToolBarCtrl object:
TBBUTTONINFO tbi; tbi.dwMask = TBIF_STYLE; tbi.cbSize = sizeof(TBBUTTONINFO); m_ToolBarCtrl.GetButtonInfo(0, &tbi); tbi.fsStyle |= TBSTYLE_DROPDOWN; m_ToolBarCtrl.SetButtonInfo(0, &tbi);
Add a TBN_DROPDOWN handler to the parent class of the toolbar object.
ON_NOTIFY(TBN_DROPDOWN, IDC_TOOLBAR1, &CMyDialog::OnTbnDropDownToolBar1)
In the new handler, display the appropriate popup menu. The following code demonstrates one method:
void CMyDialog::OnTbnDropDownToolBar1(NMHDR* pNMHDR, LRESULT* pResult) { LPNMTOOLBAR pToolBar = reinterpret_cast<LPNMTOOLBAR>(pNMHDR); ClientToScreen(&(pToolBar->rcButton)); // TrackPopupMenu uses screen coords CMenu menu; VERIFY(menu.LoadMenu(IDR_MENU1)); CMenu* pPopup = menu.GetSubMenu(0); if (NULL != pPopup) { pPopup->TrackPopupMenu(TPM_LEFTALIGN | TPM_RIGHTBUTTON, pToolBar->rcButton.left, pToolBar->rcButton.bottom, this); } *pResult = 0; }