Why does GetSafeHwnd() return zero in an ActiveX control?

1
votes

I have developed a MFC Activex control which is windowless and invisible in runtime, while i assumed that basically an activex is a control that would manipulate a windows handle, i have used GetSafeHwnd() to get windows handle, but unfortunately this method returns zero when it runs. maybe i had set wrong option when creating my activex. how i can create a windowless activex which could manipulate windows hanlde?

1
c++visual-studio-2010mfcactivex
A windowless control by definition doesn't have a window. Do you want a message-only window? – David Heffernan
i want to map a user defiened message to my app. – m-abdi
Can you show code that creates the window? – David Heffernan
my activex control doesn't have the window – m-abdi
I'm no expert on MFC or ActiveX, but you seem to be asking why a control that has no window has now window. I imagine that you need to create a window. – David Heffernan

1 Answers

2
votes

By definition, windowless ActiveX control doesn't have a window, and rendered as part of its parent. If you want to work with Windows messages in the control, you can create worker thread with a message loop, and handle any messages there. To have message loop, you don't need a window, just thread. This solution can be implemented in windowless control or in any COM component.

Alternatively, you can use windowed ActiveX control by changing its properties.