SystemParametersInfo

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This function queries or sets system-wide parameters, and updates the user profile during the process.

BOOL
SystemParametersInfo (
UINT
uiAction
,
UINT
uiParam
,
PVOID
pvParam
,
UINT
fWinIni
);

Parameters

uiAction

[in] Specifies the system-wide parameter to query or set. This parameter can be one of the following values:

Value	Description
SPI_APPBUTTONCHANGE	For Windows CE for Pocket PC and Palm-size PC, gets the application button mappings.
SPI_GETBATTERYIDLETIMEOUT	Gets the amount of time that Windows CE will stay on with battery power before it suspends due to user inaction. The pvParamparameter points to a DWORDthat returns the time in seconds. This flag is ignored if pvParamis zero.
SPI_GETEXTERNALIDLETIMEOUT	Gets the amount of time that Windows CE will stay on with AC power before it suspends due to user inaction. The pvParamparameter points to a DWORDthat returns the time in seconds. This flag is ignored if pvParamis zero.
SPI_GETMOUSE	Retrieves the two mouse threshold values and the mouse speed.
SPI_GETOEMINFO	Returns a string containing the model number and manufacturer name. The uiParamparameter specifies the length of the buffer in pvParam, which on successful return contains the string in Unicode characters.
SPI_GETPLATFORMTYPE	Returns a string specifying the type of Windows CE device, such as "H/PC." The uiParamparameter specifies the length of the buffer in pvParam, which on successful return contains the string in Unicode characters. This string allows applications like Pocket Internet Explorer to determine the device type.
SPI_GETWAKEUPIDLETIMEOUT	Gets the amount of time that Windows CE will stay on after a user notification that reactivates a suspended device. The pvParamparameter points to a DWORDthat returns the time in seconds. This flag is ignored if pvParamis zero.
SPI_GETWORKAREA	Retrieves the size of the work area on the primary screen. The work area is the portion of the screen not obscured by the system task bar or by toolbars displayed on the desktop by applications. The pvParamparameter must point to a RECTstructure that receives the coordinates of the work area, expressed in virtual screen coordinates. To get the work area of a screen other than the primary screen, call the GetMonitorInfofunction.
SPI_SETBATTERYIDLETIMEOUT	Sets the amount of time that Windows CE will stay on with battery power before it suspends due to user inaction. The Windows CE operating system will remain on, with battery power, as long as the keyboard or touch screen is active. The uiParamparameter specifies the time to set in seconds. This flag is ignored if uiParamis set to zero.
SPI_SETCURRENTIM	Sets the class identifier (CLSID) of an input method. The pvParamparameter points to a CLSIDstructure
SPI_SETDESKWALLPAPER	For Windows CE versions 2.12 and later, sets the desktop wallpaper. The value of the pvParamparameter determines the new wallpaper. To specify a wallpaper bitmap, set pvParamto point to a null-terminated string containing the name of a bitmap file. Setting pvParamto "" removes the wallpaper. Setting pvParamto SETWALLPAPER_DEFAULT or NULL reverts to the default wallpaper.
SPI_SETEXTERNALIDLETIMEOUT	Sets the amount of time that Windows CE will stay on with AC power before it suspends due to user inaction. The Windows CE operating system will remain on, with AC power, as long as the keyboard or touch screen is active. The uiParamparameter specifies the time in seconds. This flag is ignored if uiParamis set to zero.
SPI_SETMOUSE	Sets the two mouse threshold values and the mouse speed.
SPI_SETSIPINFO	Sets input panel information. The pvParamparameter points to a SIPINFOstructure.
SPI_SETWAKEUPIDLETIMEOUT	Sets the amount of time that Windows CE will stay on after a user notification that reactivates the suspended device. The uiParamparameter specifies the time in seconds. This flag is ignored if uiParamis set to zero.
SPI_SETWORKAREA	Sets the size of the work area—the portion of the screen not obscured by the system taskbar or by toolbars displayed on the desktop by applications. The pvParamparameter is a pointer to a RECTstructure that specifies the new work area rectangle, expressed in virtual screen coordinates. In a system with multiple screens, the function sets the work area of the monitor that contains the specified rectangle. If pvParamis NULL, the function sets the work area of the primary screen to the full screen.

uiParam

[in] Depends on the system parameter being queried or set. For more information about system-wide parameters, see the uiActionparameter. If not otherwise indicated, you must specify zero for this parameter.

pvParam

[out] Depends on the system parameter being queried or set. For more information about system-wide parameters, see the uiActionparameter. If not otherwise indicated, you must specify NULL for this parameter.

If the pvParambuffer is used to get the platform type or OEM information string and the buffer is too small, this function fails with ERROR_INSUFFICIENT_BUFFER in the last error.

fWinIni

[in] Boolean that, if a system parameter is being set, specifies whether the user profile is to be updated, and if so, whether the WM_SETTINGCHANGEmessage is to be broadcast to all top-level windows to notify them of the change. This parameter can be zero or can be one of the following values:

Value	Description
SPIF_UPDATEINIFILE	Writes the new system-wide parameter setting to the user profile.
SPIF_SENDCHANGE	Broadcasts the WM_SETTINGCHANGE message after updating the user profile.

Return Values

Nonzero indicates success. Zero indicates failure. To get extended error information, call GetLastError.

Remarks

This function is intended for use with applications, such as the Control Panel, that allow the user to customize the environment.

Windows CE supports only the Unicode version of this function.

Requirements

Runs on	Versions	Defined in	Include	Link to
Windows CE OS	2.0 and later	Winuser.h		Coredll.lib

Note This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.