This function queries or sets system-wide parameters, and updates the user profile during the process.
At a Glance
| Header file: | Winuser.h |
| Windows CE versions: | 2.0 and later |
Syntax
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_GETBATTERYIDLETIMEOUT | Gets the amount of time that Windows CE will stay on with battery power before it suspends due to user inaction. The pvParam parameter points to a DWORD that returns the time in seconds. This flag is ignored if pvParam is 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 pvParam parameter points to a DWORD that returns the time in seconds. This flag is ignored if pvParam is 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 uiParam parameter 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 uiParam parameter specifies the length of the buffer in pvParam, which on successful return contains the string in Unicode characters. This string allows applications like H/PC 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 pvParam parameter points to a DWORD that returns the time in seconds. This flag is ignored if pvParam is zero. |
| SPI_GETWORKAREA | Retrieves the size of the work area; the portion of the screen not obscured by the tray. |
| 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 uiParam parameter specifies the time to set in seconds. This flag is ignored if uiParam is set to zero. |
| 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 uiParam parameter specifies the time in seconds. This flag is ignored if uiParam is set to zero. | |
| SPI_SETMOUSE | Sets the two mouse threshold values and the mouse speed. |
| SPI_SETWAKEUPIDLETIMEOUT | Sets the amount of time that Windows CE will stay on after a user notification that reactivates the suspended device. The uiParam parameter specifies the time in seconds. This flag is ignored if uiParam is set to zero. |
| SPI_SETWORKAREA | Sets the size of the work area—the portion of the screen not obscured by the taskbar. |
uiParam
[in] Depends on the system parameter being queried or set. For more information about system-wide parameters, see the uiAction parameter. 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 uiAction parameter. If not otherwise indicated, you must specify NULL for this parameter.
If the pvParam buffer 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_SETTINGCHANGE message 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.
See Also