SPI_SETNONCLIENTMETRICS behaves incorrectly with Windows XP Theme causing inccorect icon sizes

[Anthony Wieser]

If you run the following code sequence, when using the Windows XP theme:

NONCLIENTMETRICS ncm, *pNCM;
ncm.cbSize = sizeof(ncm);

::SystemParametersInfo(SPI_GETNONCLIENTMETRICS, sizeof(ncm), &ncm, 0);
::SystemParametersInfo(SPI_SETNONCLIENTMETRICS, ncm.cbSize, &ncm,
SPIF_SENDCHANGE);

the icons in the system tray are grow by about 50% in size. The same does
not happen if you run it with windows classic style?

If I kill explorer.exe to restart the taskbar, and then restart it with the
run command it remains in the enlarged size, but if I log off the current
user and log back on again, the taskbar and icons revert to their normal
size. Additionally, if you start regedit after this, it will also have very
large icons shown.

Is there a known fix or workaround for this problem?

Anthony Wieser
Wieser Software Ltd