How to hook CBN_DROPDOWN and CBN_CLOSEUP ?

alikalik

Hello, I've created a new class MyComboBox, derieved from CComboBox. I need to hook CBN_DROPDOWN and CBN_CLOSEUP messages and I do it in this way:

LRESULT MyComboBox::WindowProc(UINT message, WPARAM wParam, LPARAM lParam)
{
switch(message)
{
case CBN_DROPDOWN:
fn1();
break;
case CBN_CLOSEUP:
fn2();
break;
}

return CComboBox::WindowProc(message, wParam, lParam);

}

But that doesn't work. What can cause the problem?

norish

Check http://msdn.microsoft.com/en-us/library/aa921578.aspx[^]

David Crow

Why are you not implementating handlers for CBN_DROPDOWN and CBN_CLOSEUP? What version of Visual Studio are you using?

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

alikalik

Visual Studio 2005 Standard Edition.

alikalik

LRESULT MyComboBox::WindowProc(UINT message, WPARAM wParam, LPARAM lParam)
{
switch((int)LOWORD(wParam))
{
case CBN_DROPDOWN:
fn1();
break;
}

return CComboBox::WindowProc(message, wParam, lParam);

}

I tried this already, but the problem still exists :(

norish

Have you read this part?

This message is sent when the list box of a combo box is about to be made visible.
The parent window of the combo box receives this message through the WM_COMMAND message.