Question

How to well use the WinAPI to manage the fullscreen mode on windows’s window ?

Here is my problem :

I have an application which has to be fullscreen.
I use ChangeDisplaySettings() function (winuser.h) with the CDS_FULLSCREEN value to put my window to fullscreen mode when receiving a WM_ACTIVATE with (wParam == WA_ACTIVE || wParam == WA_CLICKACTIVE) :

DEVMODE dmScreenSettings;
memset (&dmScreenSettings, 0, sizeof (dmScreenSettings));
dmScreenSettings.dmSize = sizeof (dmScreenSettings);   
dmScreenSettings.dmPelsWidth = 1280;
dmScreenSettings.dmPelsHeight = 720;    
dmScreenSettings.dmBitsPerPel = 32;      
dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;
ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN);

I use the same function with the CDS_RESET value to put it back in “normal” mode when receiving a WM_ACTIVATE with (wParam == WA_INACTIVE) :

ChangeDisplaySettings(&dmScreenSettings, CDS_RESET);

When I first launch my application, it is in fullscreen.
I use ALT+TAB to switch to another application on my computer. My application minimized itself. It works well.
Then, I switch back to my application, and it comes up in fullscreen mode. Again, it works well.
But if I want to switch back to another application one more time, my application statys in fullscreen mode, hiding all others applications on my computer.

NB : My window is created using CreateWindowEx() function with the following parameters :

DWORD dwExStyle = WS_EX_TOPMOST;
DWORD dwStyle = WS_VISIBLE | WS_POPUP;

1) Is there another way than using ChangeDisplaySettings() to change the fullscreen mode ?

2) Am I using it the good values ?

3) Is there anything to do that I forgot ?

Thanks in advance for all your answers.
Best regards,

Answer 1

These guys seem to cover all the options.

Win32: full-screen and hiding taskbar

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New Edit: Based on a new comment, try this.

Trap the WM_ACTIVATE event in you app for that window. In that event call the GetWindowPlacement Function and hopefully you’ll be on your way. Note the link to “SetWindowPlacement” at the bottom.