How to Create a drop down button in Windows Vista, 7?

In this post, I’m introducing the new button style which is introduced in Windows Vista and above. It’s no more painful to create a Drop down button with Windows Vista, earlier it was accomplished by placing two controls side by side and handle it’s message separately.

Windows Vista introduced new button style BS_SPLITBUTTON and you can set this new style by specifying as parameter of CreateWindow API if you’re dynamically creating button control or by modifying the style using ModifyStyle API. To use this style Windows Vista or higher required .

Using with CreateWindow/CButton::Create API

[sourcecode language='cpp']
HWND hWndButtonMain = CreateWindow(_T(“Button”), _T(“Split Button”),
WS_CHILD | WS_VISIBLE | BS_SPLITBUTTON,
10, 10, 120, 50,
m_hWnd, (HMENU)IDC_BTN_BUTTON1, AfxGetApp()->m_hInstance, NULL);
[/sourcecode]

Or

[sourcecode language='cpp']
CButton* pButton = new CButton;
pButton->Create( _T( “Split Button”), WS_CHILD | WS_VISIBLE | BS_SPLITBUTTON,CRect(10,10,120,50),this,IDC_BUTTON1);
[/sourcecode]

Or modifying Existing control

[sourcecode language='cpp']
m_SplitButton.ModifyStyle(0, BS_SPLITBUTTON );
[/sourcecode]

Handling Dropdown Event

Add message handler for BCN_DROPDOWN in your message handler or in message map of your MFC window class

[sourcecode language='cpp']
ON_NOTIFY(BCN_DROPDOWN, IDC_BUTTON1, &CControlSampleDlg::OnBnDropDownButton1)
[/sourcecode]

In the message Handler, Display the popup menu and the menu item can be handled using ON_COMMAND message with associated menu ID.

[sourcecode language='cpp']
void CControlSampleDlg::OnBnDropDownButton1(NMHDR *pNMHDR, LRESULT *pResult)
{
LPNMBCDROPDOWN pDropDown = reinterpret_cast(pNMHDR);

Button_SetDropDownState( m_SplitButton, TRUE );

RECT rc;

// Get the bounding rectangle of the client area
::GetWindowRect(m_SplitButton, &rc);

HMENU hmenu = LoadMenu(AfxGetApp()->m_hInstance, MAKEINTRESOURCE(IDR_MENU1));
HMENU hmenuTrackPopup;

hmenuTrackPopup = GetSubMenu(hmenu, 0);
TrackPopupMenuEx(hmenuTrackPopup, TPM_RIGHTBUTTON, rc.left, rc.bottom, m_hWnd, NULL);
DestroyMenu(hmenu);

Button_SetDropDownState( m_SplitButton, FALSE );
*pResult = 0;
}
[/sourcecode]