Type a page name and press Enter. You'll jump to the page if it exists, or you can create it if it doesn't.
To create a page in a module other than user32, prefix the name with the module name and a period.
SystemParametersInfo (user32)
.
C# Signature:
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool SystemParametersInfo(SPI uiAction, uint uiParam, ref T pvParam, SPIF fWinIni); // T = any type
Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Integer, _
ByVal uParam As Integer, ByVal lpvParam As Integer, _
ByVal fuWinIni As Integer) As Integer
Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Integer, _
ByVal uParam As Integer, ByVal lpvParam As Integer, _
ByVal fuWinIni As Integer) As Integer
<DllImport("user32", CharSet:=CharSet.Auto)> _
Public Shared Function SystemParametersInfo( _
ByVal intAction As Integer, _
ByVal intParam As Integer, _
ByVal strParam As String, _
ByVal intWinIniFlag As Integer) As Integer
' returns non-zero value if function succeeds
End Function
Notes:
For VB the strParam is an _in or _out of String type. Must be ByRef if used to query/retrieve. Otherwise use ByVal.
'=========================================================
Imports System.Runtime.InteropServices
Tips & Tricks:
When using the SPI_GETANIMATION or SPI_SETANIMATION actions, the uiParam value must be set to (System.UInt32)Marshal.SizeOf(typeof(ANIMATIONINFO)).
<DllImport("user32", CharSet:=CharSet.Auto)> _
Public Shared Function SystemParametersInfo( _
ByVal intAction As Integer, _
ByVal intParam As Integer, _
ByVal strParam As String, _
ByVal intWinIniFlag As Integer) As Integer
' returns non-zero value if function succeeds
End Function
Notes:
For VB the strParam is an _in or _out of String type. Must be ByRef if used to query/retrieve. Otherwise use ByVal.
Sample Code:
// This code works for SPI_GETFOREGROUNDLOCKTIMEOUT, the above signature doesn't. (Ken)
Tips & Tricks:
When using the SPI_GETANIMATION or SPI_SETANIMATION actions, the uiParam value must be set to (System.UInt32)Marshal.SizeOf(typeof(ANIMATIONINFO)).
// get current lock timeout value
uint timeout = 99;
bool retVal = SystemParametersInfoGet(SPI_GETFOREGROUNDLOCKTIMEOUT, 0, ref timeout, 0);
// set current lock timeout value to 0, so focus can be grabbed
SystemParametersInfoSet(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, 0, 0);
[DllImport("user32.dll", EntryPoint="SystemParametersInfo", SetLastError = true)]
public static extern bool SystemParametersInfoSet(uint action, uint param, uint vparam, uint init);
SPI_GETNONCLIENTMETRICS is a good way to get user-defined preferences for fonts, colors, icons, etc. There is no other way to do this in .NET as far as I know!
// get current lock timeout value
uint timeout = 99;
bool retVal = SystemParametersInfoGet(SPI_GETFOREGROUNDLOCKTIMEOUT, 0, ref timeout, 0);
// set current lock timeout value to 0, so focus can be grabbed
SystemParametersInfoSet(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, 0, 0);
// We can overload this definition, since that's in effect what the unmanaged
// API does anyway.
[DllImport("user32", CharSet=CharSet.Auto)]
private static extern int SystemParametersInfo(int uAction,
int uParam, ref NONCLIENTMETRICS lpvParam, int fuWinIni);
SPI_GETNONCLIENTMETRICS is a good way to get user-defined preferences for fonts, colors, icons, etc. There is no other way to do this in .NET as far as I know!
// We can overload this definition, since that's in effect what the unmanaged
// API does anyway.
[DllImport("user32", CharSet=CharSet.Auto)]
private static extern int SystemParametersInfo(int uAction,
int uParam, ref NONCLIENTMETRICS lpvParam, int fuWinIni);
private const int LF_FACESIZE = 32;
// A "logical font" used by old-school windows
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)]
private struct LOGFONT
{
public int lfHeight;
public int lfWidth;
public int lfEscapement;
public int lfOrientation;
public int lfWeight;
public byte lfItalic;
public byte lfUnderline;
public byte lfStrikeOut;
public byte lfCharSet;
public byte lfOutPrecision;
public byte lfClipPrecision;
public byte lfQuality;
public byte lfPitchAndFamily;
/// <summary>
/// <see cref="UnmanagedType.ByValTStr"/> means that the string
/// should be marshalled as an array of TCHAR embedded in the
/// structure. This implies that the font names can be no larger
/// than <see cref="LF_FACESIZE"/> including the terminating '\0'.
/// That works out to 31 characters.
/// </summary>
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=LF_FACESIZE)]
public string lfFaceName;
// to shut it up about the warnings
public LOGFONT(string lfFaceName)
{
this.lfFaceName = lfFaceName;
lfHeight = lfWidth = lfEscapement = lfOrientation = lfWeight = 0;
lfItalic = lfUnderline = lfStrikeOut = lfCharSet = lfOutPrecision
= lfClipPrecision = lfQuality = lfPitchAndFamily = 0;
}
}
private struct NONCLIENTMETRICS
{
public int cbSize;
public int iBorderWidth;
public int iScrollWidth;
public int iScrollHeight;
public int iCaptionWidth;
public int iCaptionHeight;
/// <summary>
/// Since <see cref="LOGFONT"/> is a struct instead of a class,
/// we don't have to do any special marshalling here. Much
/// simpler this way.
/// </summary>
public LOGFONT lfCaptionFont;
public int iSMCaptionWidth;
public int iSMCaptionHeight;
public LOGFONT lfSMCaptionFont;
public int iMenuWidth;
public int iMenuHeight;
public LOGFONT lfMenuFont;
public LOGFONT lfStatusFont;
public LOGFONT lfMessageFont;
}
private const int SPI_GETNONCLIENTMETRICS = 41;
OK, so here is how you query for the NONCLIENTMETRICS
Now you can use the font info however you want. Here's how to return a GDI+ Font corresponding to the MessageBox font selected by the user. Note that the height is always negative and always returns "world" units.
return new Font(Metrics.lfMessageFont.lfFaceName,
-Metrics.lfMessageFont.lfHeight,
GraphicsUnit.World);
Changing the wallpaper. Note, only works for BMP. Must convert to BMP format if using JPEG, GIF, etc. (EDIT : In Windows Vista, at least, this works with other image types, including JPEG and GIF)
VB NET Changing the Wallpaper. Note for above example applies if Window XP or below.
' before Public Class class_name
Imports System.Runtime.InteropServices
'after Public Class class_name
Const SPI_SetWallpaper As Integer = &H14
'Win.ini flag values (intWinIniFlag)
Const SPIF_UpdateIni As Integer = 1
Const SPIF_SendIniChange As Integer = 2
Const SPIF_UpdateAndSend As Integer = SPIF_UpdateIni Or SPIF_SendIniChange '3
' SetLastError:=True is required for error checking
<DllImport("user32", SetLastError:=True, CharSet:=CharSet.Auto)> _
Public Shared Function SystemParametersInfo( _
ByVal intAction As Integer, _
ByVal intParam As Integer, _
ByVal strParam As String, _
ByVal intWinIniFlag As Integer) As Integer
' returns non-zero value if function succeeds
End Function
Dim strFile as String = "WhateverFileName.bmp"
Dim intReturn As Integer = Nothing
Dim intError As Integer = Nothing
intReturn = SystemParametersInfo(SPI.SetWallpaper, 0, strFile, SPIF.UpdateAndSend)
intError = Marshal.GetLastWin32Error()
if ret <> 0 Then
' intError contains the error number
End If
Getting the path of the current desktop wallpaper:
ANIMATIONINFO - Used with SystemParametersInfo for SPI_GETANIMATION or SPI_SETANIMATION
3/16/2007 8:14:53 AM - consultants@russte.com-65.31.114.174
SPI - Used in SystemParametersInfo function
10/8/2019 12:15:28 AM - 60.231.13.173
Used in SystemParametersInfo as fWinIni
3/1/2020 3:13:14 AM - -92.208.127.193
ANIMATIONINFO - Used with SystemParametersInfo for SPI_GETANIMATION or SPI_SETANIMATION
3/16/2007 8:14:53 AM - consultants@russte.com-65.31.114.174
The SystemParametersInfo API
10/30/2013 11:50:28 AM - -212.117.77.91
The SystemParametersInfo API
10/30/2013 11:50:28 AM - -212.117.77.91
The SystemParametersInfo API
10/30/2013 11:50:28 AM - -212.117.77.91
Please edit this page!
Do you have...
helpful tips or sample code to share for using this API in managed code?
corrections to the existing content?
variations of the signature you want to share?
additional languages you want to include?
Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).
Revisions