i have a native win32 c++ application which has a checkbox in it. I want to replace the checkbox and create ON/OFF toggle button with 2 states (just like the checkbox). I've added the BS_OWNERDRAW
style to the checkbox and drawn it to the window in WM_DRAWITEM
. The problem is that when I click on the checkbox I get a WM_COMMAND
message (just like without the BS_OWNERDRAW
) but the CHECKED state doesn't change automaticly. Do I have to implement this functionality or am I missing something?
The code that handles clicking on the checkbox:
case WM_COMMAND:
wmId = LOWORD(wParam);
wmEvent = HIWORD(wParam);
switch (wmId)
{
case IDC_CHECKBOX:
if(wmEvent == BN_CLICKED)
{
dwPos = SendMessage(checkBox, BM_GETCHECK, 0, 0);
if(dwPos == BST_CHECKED )
{
// do some stuff
} else if(dwPos == BST_UNCHECKED) {
// do some stuff
}
}
The problem is that every time i click on the checkbox BM_GETCHECK returns BST_UNCHECKED. If i remove the BS_OWNERDRAW it works fine.
Code that creates the button/checkbox:
checkBox = CreateWindowEx(
0,
WC_BUTTON,
szBuffer,
WS_VISIBLE | WS_CHILD | BS_AUTOCHECKBOX | BS_OWNERDRAW,
BUTTON_ON_OFF_X, BUTTON_ON_OFF_Y,
BUTTON_ON_OFF_WIDTH, BUTTON_ON_OFF_HEIGHT,
hWnd,
(HMENU)IDC_CHECKBOX,
hInst,
NULL
);
Ordinarily, you would set BS_AUTOCHECKBOX to have the checkbox check/uncheck automatically in response to user input. However, according to the docs, you cannot combine other styles (e.g., BS_AUTOCHECKBOX) when using BS_OWNERDRAW.
http://msdn.microsoft.com/en-us/library/windows/desktop/bb775951%28v=vs.85%29.aspx