I wanted a way to know if the screen saver was running 9active) or if the screen / terminal was locked. The best way to find out is through the SystemParameterInfo class which is not provided to the .Net framework, so you have to make a call to the API for it. Now SPI has way more information than just whether the screen saver is running or if the terminal is locked, but that's all I need it for at the moment. I've included more info on how to use it at the end.
using
System.Runtime.InteropServices;
using
System.Threading;
using
log4net;
namespace
InternalInstantMessenger
{
///
<summary>
/// Summary
description for SystemParameterInfoWrapper.
///
</summary>
///
<remarks>
/// A lot of
this was found on
/// http://www.dotnet247.com/247reference/msgs/45/225361.asp
///note: this
will only work on win 2000 or higher, NT doesn't support the screensaver
running on SPI
///</remarks>
public class
SystemParameterInfoWrapper
{
public
static int
SPI_GETSCREENSAVEACTIVE = 16;
public
static int
SPI_GETSCREENSAVERRUNNING = 114;
private
static readonly
log4net.ILog log =
log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
[DllImport("user32.dll", CharSet=CharSet.Auto)]
public
static extern
int SystemParametersInfo(int
uAction,int uParam,
ref int
lpvParam, int fuWinIni);
public
static bool
IsScreenSaverRunning()
{p; {
bool running =
false;
try
{
int
screenSaverRunning = -1;
// is the screen saver
running?
int ok =
SystemParametersInfo(SPI_GETSCREENSAVERRUNNING, 0,
ref
screenSaverRunning, 0);
if (ok != 0)
{
if (screenSaverRunning
!= 0)
{p; {
// screen saver is
running
running = true;
}
}
}
catch (Exception e)
{
log.Error("Exception while determining if
screensaver is running",e);
}
return running;
}
public
SystemParameterInfoWrapper()
{p; {
}
}
Here's some more information I was able to dig up regarding using SPI, including the values for constants:
SPI_GETACCESSTIMEOUT = 60
Retrieve information about the time-out period associated with the accessibility
features. uiParam must be the size of the ACCESSTIMEOUT structure. pvParam is an
ACCESSTIMEOUT structure receiving the time-out settings.
SPI_GETANIMATION = 72
Win 95/98 only: Retrieve information about the animation effects associated with
the user's actions. uiParam must be 0. pvParam is an ANIMATIONINFO structure
receiving the animation effects settings.
SPI_GETBEEP = 1
Determine if the warning beeper is on or off. uiParam must be 0. pvParam is a
Long-type variable which receives 0 if the warning beeper is off, or a non-zero
value if it is on.
SPI_GETBORDER = 5
Retrieve the window sizing border multiplier factor, which determines the width
of a window's sizing border. uiParam must be 0. pvParam is a Long-type variable
which receives the current setting.
SPI_GETDEFAULTINPUTLANG = 89
Win 95/98 only: Retrieve a handle to the keyboard layout used for the system's
default input language. uiParam must be 0. pvParam is a Long-type variable which
receives the handle.
SPI_GETDRAGFULLWINDOWS = 38
Win 95/98 only: Determine if Windows displays the entire contents of a window
when it is moved or resized (instead of merely displaying an outline of it).
uiParam must be 0. pvParam is a Long-type variable which receives 0 if the
contents are not displayed, or a non-zero value if they are.
SPI_GETFASTTASKSWITCH = 35
Determine if fast Alt-Tab task switching is enabled. uiParam must be 0. pvParam
is a Long-type variable which receives 0 if fast task switching is not enabled,
or a non-zero value if it is.
SPI_GETFILTERKEYS = 50
Retrieve the settings of the FilterKeys accessibility feature. uiParam must be
the size of the FILTERKEYS structure. pvParam is a FILTERKEYS structure which
receives the current settings of FilterKeys.
SPI_GETFONTSMOOTHING = 74
Determine whether font smoothing is enabled or not. uiParam must be 0. pvParam
is a Long-type variable which receives 0 if font smoothing is not enabled, or a
non-zero value if it is.
SPI_GETGRIDGRANULARITY = 18
Retrieve the current granularity of the desktop sizing grid. uiParam must be 0.
pvParam is a Long-type variable which receives the current setting.
SPI_GETHIGHCONTRAST = 66
Win 95/98 only: Retrieve the settings of the HighContrast accessibility feature.
uiParam must be 0. pvParam is a HIGHCONTRAST structure which receives the
current settings of HighContrast.
SPI_GETICONMETRICS = 45
Win 95/98 only: Retrieve the metrics associated with icons, which determine how
Windows displays icons. uiParam must be 0. pvParam is an ICONMETRICS structure
which receives the icon metrics.
SPI_GETICONTITLELOGFONT = 31
Retrieve information about the logical font used to display the titles of icons.
uiParam must be the size of the LOGFONT structure. pvParam is a LOGFONT
structure which receives information about the logical font.
SPI_GETICONTITLEWRAP = 25
Determine if Windows word-wraps the text of icon titles. uiParam must be 0.
pvParam is a Long-type variable which receives 0 if word-wrapping is not
enabled, or a non-zero value if it is.
SPI_GETKEYBOARDDELAY = 22
Retrieve the current keyboard repeat delay setting, which is the time before a
held key begins to repeat. uiParam must be 0. pvParam is a Long-type variable
which receives the current delay setting (a value between 0 and 3).
SPI_GETKEYBOARDPREF = 68
Win 95/98 only: Determine if the user relies on the keyboard instead of the
mouse and wants programs to display keyboard interfaces which are otherwise
hidden. uiParam must be 0. pvParam is a Long-type variable which receives 0 if
the user does not rely on the keyboard, or a non-zero value if the user does.
SPI_GETKEYBOARDSPEED = 10
Retrieve the current keyboard repeat speed setting, which is the speed between
repeats when a key is held. uiParam must be 0. pvParam is a Long-type variable
which receives the current speed setting (a value between 0 and 31).
SPI_GETLOWPOWERACTIVE = 83
Win 95/98 only: Determine if the system enters a low-power mode after a period
of inactivity. uiParam must be 0. pvParam is a Long-type variable which receives
0 if low-power mode is not enabled, or a non-zero value if it is.
SPI_GETLOWPOWERTIMEOUT = 79
Win 95/98 only: Retrieve the time, in seconds, which must elapse before Windows
enters low-power mode. uiParam must be 0. pvParam is a Long-type variable which
receives the current timeout value.
SPI_GETMENUDROPALIGNMENT = 27
Determine if popup menus are left- or right-aligned. uiParam must be 0. pvParam
is a Long-type variable which receives 0 if the menus are right-aligned, or a
non-zero value if they are left-aligned.
SPI_GETMINIMIZEDMETRICS = 43
Win 95/98 only: Retrieve the metrics associated with minimized windows, which
specify how Windows displays minimized windows. uiParam must be the size of the
MINIMIZEDMETRICS structure. pvParam is a MINIMIZEDMETRICS structure which
receives the minimized window metrics.
SPI_GETMOUSE = 3
Retrieve the x-axis and y-axis threshold values for the mouse as well as the
mouse speed. uiParam must be 0. pvParam is a 3-element array of Long-type
variables which receives the x-threshold, y-threshold, and mouse speed.
SPI_GETMOUSEKEYS = 54
Retrieve the settings of the MouseKeys accessibility feature. uiParam must be
the size of the MOUSEKEYS structure. pvParam is a MOUSEKEYS structure which
receives the current settings of MouseKeys.
SPI_GETMOUSETRAILS = 94
Win 95/98 only: Retrieve the current mouse trails setting. uiParam must be 0.
pvParam receives 0 or 1 if mouse trails are not enabled, or a value greater than
one identifying the number of cursor images making up the mouse trail.
SPI_GETNONCLIENTMETRICS = 41
Win 95/98 only: Retrieve the metrics associated with the nonclient areas of
windows, which determine how Windows renders nonclient areas. uiParam must be 0.
pvParam is a NONCLIENTMETRICS structure which receives the nonclient area
metrics.
SPI_GETPOWEROFFACTIVE = 84
Win 95/98 only: Determine if the system enters a power-off mode after a period
of inactivity. uiParam must be 0. pvParam is a Long-type variable which receives
0 if power-off mode is not enabled, or a non-zero value if power-off mode is
enabled.
SPI_GETPOWEROFFTIMEOUT = 80
Win 95/98 only: Retrieve the time-out value, in seconds, that must elapse before
Windows enters power-off mode. uiParam must be 0. pvParam is a Long-type
variable which receives the time-out value for power-off mode.
SPI_GETSCREENREADER = 70
Win 95/98 only: Determine if a screen reader utility is running. If it is,
applications should present more textual output instead of graphical output to
help the reader function better. uiParam must be 0. pvParam is a Long-type
variable which receives 0 if no screen reader is running, or a non-zero value if
one is.
SPI_GETSCREENSAVEACTIVE = 16
Determine if a screen saver is set to run. uiParam must be 0. pvParam is a
Long-type variable which receives 0 if no screen saver is set to run, or a
non-zero value if one is.
SPI_GETSCREENSAVETIMEOUT = 14
Retrieve the time-out period, in seconds, which must elapse before the screen
saver begins running. uiParam must be 0. pvParam is a Long-type variable which
receives the time-out value.
SPI_GETSERIALKEYS = 62
Win 95/98 only: Retrieve the settings of the SerialKeys accessibility feature.
uiParam must be 0. pvParam is a SERIALKEYS structure which receives the current
settings of SerialKeys.
SPI_GETSHOWSOUNDS = 56
Determine if the user desires visual information to replace or suppliment
otherwise audio-only output. uiParam must be 0. pvParam is a Long-type variable
which receives 0 if programs should not display this added visual information,
or a non-zero value if they should.
SPI_GETSOUNDSENTRY = 64
Retrieve the settings of the SoundSentry accessibility feature. uiParam must be
the size of the SOUNDSENTRY structure. pvParam is a SOUNDSENTRY structure which
receives the current settings of SoundSentry.
SPI_GETSTICKYKEYS = 58
Retrieve the settings of the StickyKeys accessibility feature. uiParam must be
the size of the STICKYKEYS structure. pvParam is a STICKYKEYS structure which
receives the settings of StickyKeys.
SPI_GETTOGGLEKEYS = 52
Retrieve the settings of the ToggleKeys accessibility feature. uiParam must be
the size of the TOGGLEKEYS structure. pvParam is a TOGGLEKEYS structure which
receives the current settings of ToggleKeys.
SPI_GETWINDOWSEXTENSION = 92
Win 95/98 only: Determine if the Windows extensions are installed. Win 95
requires that Microsoft Plus! be installed to get the extensions; the extensions
are integrated as a part of Win 98. uiParam must be 1. pvParam must be 0. The
function returns 0 if the extensions are disabled, or a non-zero value if they
are enabled.
SPI_GETWORKAREA = 48
Win 95/98 only: Retrieve the size of the working area, which is a rectangle
identifying the area of the desktop not obscured by the taskbar. uiParam must be
0. pvParam is a RECT structure which receives the rectangle of the working area.
SPI_ICONHORIZONTALSPACING = 13
Set the width of the icon spacing cell. uiParam is the new setting for the
width. pvParam must be 0.
SPI_ICONVERTICALSPACING = 24
Set the height of the icon spacing cell. uiParam is the new setting for the
height. pvParam must be 0.
SPI_LANGDRIVER = 12
Win 95/98 only: Retrieve the filename of the language driver. uiParam must be 0.
pvParam is a String (with sufficient buffer space) which receives the filename
of the language driver.
SPI_SETACCESSTIMEOUT = 61
Set information associated with the time-out period associated with the
accessibility features. uiParam must be the size of the ACCESSTIMEOUT structure.
pvParam is an ACCESSTIMEOUT structure holding the new time-out period settings.
SPI_SETANIMATION = 73
Win 95/98 only: Set information about the animation effects associated with the
user's actions. uiParam must be 0. pvParam is an ANIMATIONINFO structure holding
the new animation effects settings.
SPI_SETBEEP = 2
Turn the warning beeper on or off. uiParam is 0 to turn the beeper off, or a
non-zero value to turn it on. pvParam must be 0.
SPI_SETBORDER = 6
Set the window sizing border multiplier factor, which determines the width of a
window's sizing border. uiParam is the new setting. pvParam must be 0.
SPI_SETCURSORS = 87
Reload the images used for the system cursors. uiParam and pvParam must be 0.
SPI_SETDEFAULTINPUTLANG = 90
Win 95/98 only: Set the keyboard layout used for the system's default input
language. uiParam is a handle to the keyboard layout to use. pvParam must be 0.
SPI_SETDESKPATTERN = 21
Set the current desktop pattern bitmap by causing Windows to reread the Pattern
setting in the [Desktop] section of WIN.INI. Both uiParam and pvParam must be 0.
SPI_SETDESKWALLPAPER = 20
Set the current desktop wallpaper bitmap. uiParam must be 0. pvParam is a String
holding the filename of the bitmap file to use as the wallpaper.
SPI_SETDOUBLECLICKTIME = 32
Set the time, in milliseconds, within which two successive mouse clicks must
occur for Windows to interpret the input to be a double click. uiParam is the
new double click time. pvParam must be 0.
SPI_SETDOUBLECLKHEIGHT = 30
Set the height of the rectangle within which two successive mouse clicks must
occur for Windows to interpret the input to be a double click. uiParam is the
new height. pvParam must be 0.
SPI_SETDOUBLECLKWIDTH = 29
Set the width of the rectangle within which two successive mouse clicks must
occur for Windows to interpret the input to be a double click. uiParam is the
new width. pvParam must be 0.
SPI_SETDRAGFULLWINDOWS = 37
Win 95/98 only: Turn dragging of full windows (displaying the contents of a
window while moving or resizing instead of just an empty border) on or off.
uiParam is 0 to turn dragging of full windows off, or a non-zero value to turn
it on.
SPI_SETDRAGHEIGHT = 77
Win 95/98 only: Set the height of the rectangle which the cursor must move out
of with a button depressed for Windows to begin a drag operation. uiParam is the
new height. pvParam must be 0.
SPI_SETDRAGWIDTH = 76
Win 95/98 only: Set the width of the rectangle which the cursor must move out of
with a button depressed for Windows to begin a drag operation. uiParam is the
new width. pvParam must be 0.
SPI_SETFASTTASKSWITCH = 36
Turn fast Alt-Tab task switching on or off. uiParam is 0 to turn fast switching
off, or a non-zero value to turn it on. pvParam must be 0.
SPI_SETFILTERKEYS = 51
Set the settings of the FilterKeys accessibility feature. uiParam must be the
size of the FILTERKEYS structure. pvParam is a FILTERKEYS structure holding the
new settings for FilterKeys.
SPI_SETFONTSMOOTHING = 75
Turn font smoothing on or off. uiParam is 0 to turn font smoothing off, or a
non-zero value to turn it on.
SPI_SETGRIDGRANULARITY = 19
Set the granularity of the desktop sizing grid. uiParam is the new setting.
pvParam must be 0.
SPI_SETHIGHCONTRAST = 67
Win 95/98 only: Set the settings of the HighContrast accessibility feature.
uiParam must be 0. pvParam is a HIGHCONTRAST structure holding the new settings
for HighContrast.
SPI_SETICONMETRICS = 46
Win 95/98 only: Set the metrics associated with icons, which specify how Windows
displays icons. uiParam must be 0. pvParam is an ICONMETRICS structure holding
the new icon metrics.
SPI_SETICONS = 88
Reload the images used for the system icons. uiParam and pvParam must be 0.
SPI_SETICONTITLELOGFONT = 34
Set the logical font used to display the text of icon titles. uiParam must be
the size of the LOGFONT structure. pvParam is a LOGFONT structure holding the
logical font to use.
SPI_SETICONTITLEWRAP = 26
Turn the word-wrapping of icon titles on or off. uiParam is 0 to turn
word-wrapping off, or a non-zero value to turn it on. pvParam must be 0.
SPI_SETKEYBOARDDELAY = 23
Set the keyboard repeat-delay setting, which is the time that must elapse before
a held key begins to repeat. uiParam is the new delay setting, between 0 and 3
inclusive. pvParam must be 0.
SPI_SETKEYBOARDPREF = 69
Win 95/98 only: Tell Windows whether the user depends on the keyboard as the
main input device and wishes programs to display additional keyboard-based
interfaces. uiParam is 0 to not indicate a keyboard preference, or a non-zero
value to indicate one. pvParam must be 0.
SPI_SETKEYBOARDSPEED = 11
Set the keyboard repeat-speed setting, which specifies the rate at which keys
are repeated. uiParam is the new speed setting, between 0 and 31 inclusive.
pvParam must be 0.
SPI_SETLANGTOGGLE = 91
Win 95/98 only: Set the hot key used to switch keyboard input languages. The new
value is read from the registry at HKEY_CURRENT_USER\keyboard layout\toggle: 1
sets the hot key to ALT+SHIFT, 2 sets the hot key to CTRL+SHIFT, and 3 disables
the hot key. uiParam and pvParam must be 0.
SPI_SETLOWPOWERACTIVE = 85
Win 95/98 only: Turn the low-power mode after a period of inactivity on or off.
uiParam is 0 to deactivate low-power mode, or 1 to activate to. pvParam must be
0.
SPI_SETLOWPOWERTIMEOUT = 81
Win 95/98 only: Set the time-out period (in seconds) which must elapse after
user input before Windows enters low-power mode. uiParam is the new time-out
period. pvParam must be 0.
SPI_SETMENUDROPALIGNMENT = 28
Set whether pop-up menus open to the left or to the right. uiParam is 0 if they
open to the left, or a non-zero value if they open to the right. pvParam must be
0.
SPI_SETMINIMIZEDMETRICS = 44
Win 95/98 only: Set the metrics associated with minimized windows, which
determine how Windows displays minimized windows. uiParam must be 0. pvParam is
a MINIMIZEDMETRICS structure holding the new metrics.
SPI_SETMOUSE = 4
Set the x-axis and y-axis threshold values for the mouse as well as the mouse
speed. uiParam must be 0. pvParam is a three-element Long-type array; the first
element is the x-threshold, the second element is the y-threshold, and the third
element is the mouse speed.
SPI_SETMOUSEBUTTONSWAP = 33
Swap or unswap the meanings of the left and right mouse buttons. uiParam is 0 to
restore the left-to-left/right-to-right mapping, or a non-zero value to swap the
buttons into a left-to-right/right-to-left mapping. pvParam must be 0.
SPI_SETMOUSEKEYS = 55
Set the settings of the MouseKeys accessibility feature. uiParam must be the
size of the MOUSEKEYS structure. pvParam is a MOUSEKEYS structure holding the
new settings for MouseKeys.
SPI_SETMOUSETRAILS = 93
Win 95/98 only: Set the length of the mouse trail. uiParam is 0 or 1 to turn
mouse trails off, or a value greater than one identifying the number of cursor
images used to make up the mouse trail. pvParam must be 0.
SPI_SETNONCLIENTMETRICS = 42
Win 95/98 only: Set the metrics associated with the non-client areas of windows,
which determine how Windows displays the non-client areas. uiParam must be 0.
pvParam is a NONCLIENTMETRICS structure holding the new metrics.
SPI_SETPENWINDOWS = 49
Win 95/98 only: Load or unload Microsoft Pen for Windows, if available. uiParam
is 0 to unload Pen, or a non-zero value to load Pen. pvParam must be 0.
SPI_SETPOWEROFFACTIVE = 86
Win 95/98 only: Set whether the system powers down after a period of inactivity.
uiParam is 0 to not enter power-off mode, or a non-zero value to enter power-off
mode. pvParam must be 0.
SPI_SETPOWEROFFTIMEOUT = 82
Win 95/98 only: Set the time-out period, in seconds, which must elapse without
user input before Windows enters power-off mode. uiParam is the new time-out
period. pvParam must be 0.
SPI_SETSCREENREADER = 71
Win 95/98 only: Set whether a screen-reading program is currently running.
uiParam is 0 if no reader is in use, or a non-zero value if one is. pvParam must
be 0.
SPI_SETSCREENSAVEACTIVE = 17
Set whether Windows activates a screen saver after a period of inactivity.
uiParam is 0 to turn the screen saver off, or a non-zero value to turn it on.
pvParam must be 0.
SPI_SETSCREENSAVETIMEOUT = 15
Set the time-out period, in seconds, which must elapse before Windows launches a
screen saver. uiParam is the new time-out period. pvParam must be 0.
SPI_SETSERIALKEYS = 63
Win 95/98 only: Set the settings of the SerialKeys accessibility feature.
uiParam must be 0. pvParam is a SERIALKEYS structure holding the new settings
for SerialKeys.
SPI_SETSHOWSOUNDS = 57
Turn the ShowSounds accessibility feature on or off. uiParam is 0 to turn
ShowSounds off, or a non-zero value to turn ShowSounds on. pvParam must be 0.
SPI_SETSOUNDSENTRY = 65
Set the settings of the SoundSentry accessibility feature. uiParam must be the
size of the SOUNDSENTRY structure. pvParam is a SOUNDSENTRY structure holding
the new settings for SoundSentry.
SPI_SETSTICKYKEYS = 59
Set the settings of the StickyKeys accessibility feature. uiParam is the size of
the STICKYKEYS structure. pvParam is a STICKYKEYS structure holding the new
settings for StickyKeys.
SPI_SETTOGGLEKEYS = 53
Set the settings of the ToggleKeys accessibility feature. uiParam is the size of
the TOGGLEKEYS structure. pvParam is a TOGGLEKEYS structure holding the new
settings for ToggleKeys.
SPI_SETWORKAREA = 47
Win 95/98 only: Set the rectangle defining the working area of the desktop. The
working area is the area of the desktop not obscured by the taskbar. uiParam
must be 0. pvParam is a RECT structure holding the new working area rectangle.