| BOOL SystemParametersInfo(wAction, wParam, lpvParam, fWinIni) | |||||
| UINT wAction; | /* system parameter to query or set | */ | |||
| UINT wParam; | /* depends on wAction parameter | */ | |||
| PVOID lpvParam; | /* depends on wAction parameter | */ | |||
| UINT fWinIni; | /* WIN.INI update flag | */ | |||
The SystemParametersInfo function queries or sets system-wide parameters. This function can also update the WIN.INI file while setting a parameter, depending on the value of the fWinIni parameter.
wAction
Specifies the system-wide parameter to query or set, which may be one of the following:
| Value | Meaning |
| SPI_GETBEEP | ||
| Retrieves a BOOL value that indicates whether the warning beeper is on or off. | ||
| SPI_GETBORDER | ||
| Retrieves the border multiplier factor that determines the width of a window's sizing border. | ||
| SPI_GETGRIDGRANULARITY | ||
| Retrieves the current granularity value of the desktop sizing grid. | ||
| SPI_GETICONTITLELOGFONT | ||
| Retrieves the logical font information for the current icon-title font. | ||
| SPI_GETICONTITLEWRAP | ||
| Determines whether icon title wrapping is on or off. | ||
| SPI_GETKEYBOARDDELAY | ||
| Retrieves the keyboard repeat-delay setting. | ||
| SPI_GETKEYBOARDSPEED | ||
| Retrieves the keyboard repeat-speed setting. | ||
| SPI_GETMENUDROPALIGNMENT | ||
| Determines whether popup menus are left aligned or right aligned relative to the corresponding menu-bar item. | ||
| SPI_GETMOUSE | ||
| Retrieves the mouse speed and the x and y mouse threshold values. | ||
| SPI_GETSCREENSAVEACTIVE | ||
| Retrieves a BOOL value that indicates whether screen saving is on or off. | ||
| SPI_GETSCREENSAVETIMEOUT | ||
| Retrieves the screen-saver timeout value. | ||
| SPI_ICONHORIZONTALSPACING | ||
| Sets the width (in pixels) of an icon cell. | ||
| SPI_ICONVERTICALSPACING | ||
| Sets the height (in pixels) of an icon cell. | ||
| SPI_LANGDRIVER | ||
| Identifies the language driver. | ||
| SPI_SETBEEP | ||
| Turns the warning beeper on or off. | ||
| SPI_SETBORDER | ||
| Sets the border multiplier factor that determines the width of a window's sizing border. | ||
| SPI_SETDESKPATTERN | ||
| Sets the current desktop pattern by causing the Windows USER.EXE program to read the “Pattern=” parameter from the WIN.INI file. | ||
| SPI_SETDESKWALLPAPER | ||
| Specifies the filename that contains the bitmap to be used as the desktop wallpaper. | ||
| SPI_SETDOUBLECLKHEIGHT | ||
| Sets the height of the rectangle within which the second click of a double click must fall for it to be registered as a double click. | ||
| SPI_SETDOUBLECLICKTIME | ||
| Sets the double-click time for the mouse. The double-click time is the maximum number of milliseconds that may occur between the first and second clicks of a double-click. | ||
| SPI_SETDOUBLECLKWIDTH | ||
| Sets the width of the rectangle within which the second click of a double click must fall for it to be registered as a double click. | ||
| SPI_SETGRIDGRANULARITY | ||
| Sets the granularity of the desktop sizing grid. | ||
| SPI_SETICONTITLEWRAP | ||
| Turns icon title wrapping on or off. | ||
| SPI_SETKEYBOARDDELAY | ||
| Sets the keyboard repeat-delay setting. | ||
| SPI_SETKEYBOARDSPEED | ||
| Sets the keyboard repeat-speed setting. | ||
| SPI_SETMENUDROPALIGNMENT | ||
| Sets the alignment value of popup menus. | ||
| SPI_SETMOUSE | ||
| Sets the mouse speed and the x and y mouse threshold values. | ||
| SPI_SETMOUSEBUTTONSWAP | ||
| Swaps or restores the meaning of the left and right mouse buttons. | ||
| SPI_SETSCREENSAVEACTIVE | ||
| Sets the state of the screen saver. | ||
| SPI_SETSCREENSAVETIMEOUT | ||
| Sets the screen-saver timeout value. | ||
wParam
This parameter depends on the wAction parameter. See the following Comments section for details.
lpvParam
This parameter depends on the wAction parameter. See the following Comments section for details.
fWinIni
If a system parameter is being set, this parameter specifies whether the WIN.INI file is updated, and if so, whether the WM_WININICHANGE message is broadcast to all top-level windows to notify them of the change. This parameter can be one of the following values:
| Value | Meaning |
| SPIF_UPDATEINIFILE | ||
| Writes the new system-wide parameter setting to the WIN.INI file. | ||
| SPIF_SENDWININICHANGE | ||
| Broadcasts the WM_WININICHANGE message after updating the WIN.INI file. | ||
The return value is TRUE if the function is successful, or FALSE if an error occurred.
This function is intended for applications such as Control Panel that allow the user to customize the Windows environment.
The following table describes the wParam and lpvParam parameters for each SPI_ constant:
| Constant | wParam | lpvParam |
| SPI_GETBEEP | 0 | Points to a BOOL variable that receives TRUE if the beeper is on, FALSE if it is off. | |
| SPI_GETBORDER | 0 | Points to an integer variable that receives the border multiplier factor. | |
| SPI_GETGRIDGRANULARITY | 0 | Points to an integer variable that receives the grid-granularity value. | |
| SPI_GETICONTITLELOGFONT | Specifies the size of a LOGFONT structure. | Points to a LOGFONT structure that receives the logical font information. | |
| SPI_GETICONTITLEWRAP | 0 | Points to a BOOL variable that receives TRUE if wrapping if on, FALSE if wrapping is off. | |
| SPI_GETKEYBOARDDELAY | 0 | Points to an integer variable that receives the keyboard repeat-delay setting. | |
| SPI_GETKEYBOARDSPEED | 0 | Points to a WORD variable that receives the current keyboard repeat-speed setting. | |
| SPI_GETMENUDROPALIGNMENT | 0 | Points to a BOOL variable that receives TRUE if popup menus are right aligned, FALSE if they are left aligned. | |
| SPI_GETMOUSE | 0 | Points to an integer array where lpiMouse[0] receives xMouseThreshold, lpiMouse[1] receives yMouseThreshold, and lpiMouse[2] receives MouseSpeed. | |
| SPI_GETSCREENSAVEACTIVE | 0 | Points to a BOOL variable that receives TRUE if the screen saver is active, FALSE if it is not. | |
| SPI_GETSCREENSAVETIMEOUT | 0 | Points to an integer variable that receives the screen-saver timeout value (in milliseconds). | |
| SPI_ICONHORIZONTALSPACING | Specifies the icon cell width. | NULL | |
| SPI_ICONVERTICALSPACING | Specifies the icon cell height. | NULL | |
| SPI_LANGDRIVER | 0 | Points to a string containing the new language driver filename. | |
| SPI_SETBEEP | TRUE turns the beeper on; FALSE turns the beeper off. | NULL | |
| SPI_SETBORDER | Specifies the border multiplier factor. | NULL | |
| SPI_SETDESKPATTERN | 0 | NULL | |
| SPI_SETDESKWALLPAPER | 0 | Points to a string that specifies the name of the bitmap file. | |
| SPI_SETDOUBLECLKHEIGHT | Specifies the double-click height (in pels). | NULL | |
| SPI_SETDOUBLECLICKTIME | Specifies the double-click time (in milliseconds). | NULL | |
| SPI_SETDOUBLECLKWIDTH | Specifies the double-click width (in pels). | NULL | |
| SPI_SETGRIDGRANULARITY | Specifies the grid granularity. | ||
| SPI_SETICONTITLEWRAP | TRUE turns wrapping on; FALSE turns wrapping off. | NULL | |
| SPI_SETKEYBOARDDELAY | Specifies the keyboard-delay setting. | NULL | |
| SPI_SETKEYBOARDSPEED | Specifies the repeat-speed setting. | NULL | |
| SPI_SETMENUDROPALIGNMENT | TRUE specifies right alignment, FALSE specifies left alignment. | NULL | |
| SPI_SETMOUSE | 0 | Points to an integer array where lpiMouse[0] receives xMouseThreshold, lpiMouse[1] receives yMouseThreshold, and lpiMouse[2] receives MouseSpeed. | |
| SPI_SETMOUSEBUTTONSWAP | TRUE reverses the meaning of the left and right mouse buttons, FALSE restores the buttons to their original meaning. | NULL | |
| SPI_SETSCREENSAVEACTIVE | TRUE activates screen saving; FALSE deactivates screen saving. | NULL | |
| SPI_SETSCREENSAVETIMEOUT | Specifies the idle time-out duration (in seconds) before the screen is saved. | NULL | |