🚀 go-pugleaf

Hi everyone, just wondering if anyone could help me out with a small
problem.  It's small, but it takes some explaining so here goes:

Under Explorer (the desktop) when you change the colour depth of the screen,
explorer reloads all the images (icons) that it is displaying so that it
displays them correctly.  When I examine the resource files for the system
i.e. shell32.dll I can see that each icon actually consists of many sub
icons, one for each size (48x48, 32x32 and 16x16) and one for each colour
(16 bit and 256 bit).  So I assume that explorer simply calls
MAKEINTRESOURCE with the numeric ID for the icon and inturn MAKEINTRESOURCE
returns a string ID which relates to the icon.  In turn this is passed to
LoadIcon which loads the relevant icon which most suites the screen
resolution and icon size.  This is described in the help file, thus:

"LoadIcon loads the icon resource only if it has not been loaded; otherwise,
it retrieves a handle to the existing resource. The function searches the
icon resource for the icon most appropriate for the current display."


Now I'm trying to achieve the same thing.  I have many icons in a resource
file.  Under each icon is all the relevent sub icons of different sizes and
colours.  At run time I load up the icons using the LoadIcon API, i.e.

   imgOpt->Picture->Icon->Handle = LoadIcon(HInstance,
MAKEINTRESOURCE(101));

-  Now this workes fine.  If I set my screen resolution to 256 colour and
then run my application, I see the correct icon being displayed for 256
colours.  If I close my application, change the screen resolution down to 16
bit colour and then run my app again, I see the correct icon being displayed
for the 16 bit colour.

However the problem occures when I try to reload the icons, at run-time, in
responce to the screen resolution being changed WHILST the application is
running.  In order to do this I create a Message Map and look for the
message WM_DISPLAYCHANGE.  I check the values and then call my Image load
function.  However I see the same icon (in this case, for the higher screen
resolution) being displayed.  I assume this is because LoadIcon has already
loaded the icon once and so it simply retures the existing handle.  It
doesn't matter what I do.  I've tried to NULLify the Handle, I've tried
creating a secondard dialog and loading the icons in there, then closing and
explisitly destroying it - just to test the problem.  When I re-display the
dialog and get the oringinal icon being displayed.

I really need to resolve this problem, I have a LoadGraphics method in each
of my forms and I need to recall it in responce to the screen changing.  I
need some way to 'reset' LoadIcon. Any ideas would be excellent (except
splitting all my icons up and then checking the screen resoloution in order
to determine which one to load, manually).  I hope I've explained this
problem correctly.  I've written a test applicaton that demonstrates this
perfectly - I can upload it or e-mail it to where ever - if someone can tell
me where.

Many, Many thanks in advance,

Mike C