Re: Delegate.BeginInvoke and EndInvoke.

The documentation for SystemParametersInfo details sending the cbSize
value for SPI_{G|S}ETCLIENTMETRICS; but I tried with 0 and it seems to
work too (the same value is in NONCLIENTMETRICS, so it doesn't *need* it).

Okay, a little bit of testing shows that SystemParametersInfo (at least
with SPI_SETCLIENTMETRICS) is blocking, but it doesn't block the GUI
thread and it continues to pump messages.  In my test, while blocked on
the SystemParametersInfo(SPI_SETCLIENTMETRICS) the thread received the
following messages:
WM_WINDOWPOSCHANGING
WM_GETMINMAXINFO
WM_NCCALCSIZE
WM_WINDOPOSCHANGED

You can certainly get in a situation--since a function call is blocked and
messages can come in on the same thread while that's blocked--where you
can cause a hang.