A customer had a problem where one of their program's
windows was somehow receiving the
extended window style, thereby becoming topmost.
The scenario was that they created a popup window with the
and subsequently opened a document window.
If they destroyed the popup window before creating the document
window, then everything was fine.
But if they created the document window before destroying the
then their main app magically gained the
Their investigation revealed that nobody was calling
Are there other ways that a window can become topmost?
One way that a window can become topmost is if it is created
Another way that a window can become topmost is if you
SetWindowPos and pass
TOPMOST as the
Yet another way that a window can become topmost is if you
pass a topmost window as the
Armed with this information, the customer did some more
investigation and reported back:
They found a call to
SetWindowPos that was
making the window topmost.
Not that anybody should be doing that anyway.
The documentation for the
says that you shouldn't be manipulating the extended style
"To add or remove this style, use the