by Anonymous (267 Submissions)
Category: Windows System Services
Compatability: Visual Basic 4.0 (32-bit)
Difficulty: Unknown Difficulty
Originally Published: Mon 14th December 1998
Date Added: Mon 8th February 2021
Rating: 
(1 Votes)
Change the Windows display resolution.
API Declarations
Public Const EWX_SHUTDOWN = 1
Public Const EWX_REBOOT = 2
Public Const EWX_FORCE = 4
Public Const CCDEVICENAME = 32
Public Const CCFORMNAME = 32
Public Const DM_BITSPERPEL = &H40000
Public Const DM_PELSWIDTH = &H80000
Public Const DM_PELSHEIGHT = &H100000
Public Const CDS_UPDATEREGISTRY = &H1
Public Const CDS_TEST = &H4
Public Const DISP_CHANGE_SUCCESSFUL = 0
Public Const DISP_CHANGE_RESTART = 1
Type typDevMODE
dmDeviceName As String * CCDEVICENAME
dmSpecVersion As Integer
dmDriverVersion As Integer
dmSize As Integer
dmDriverExtra As Integer
dmFields As Long
dmOrientation As Integer
dmPaperSize As Integer
dmPaperLength As Integer
dmPaperWidth As Integer
dmScale As Integer
dmCopies As Integer
dmDefaultSource As Integer
dmPrintQuality As Integer
dmColor As Integer
dmDuplex As Integer
dmYResolution As Integer
dmTTOption As Integer
dmCollate As Integer
dmFormName As String * CCFORMNAME
dmUnusedPadding As Integer
dmBitsPerPel As Integer
dmPelsWidth As Long
dmPelsHeight As Long
dmDisplayFlags As Long
dmDisplayFrequency As Long
End Type
Declare Function EnumDisplaySettings Lib "user32" Alias "EnumDisplaySettingsA" (ByVal lpszDeviceName As Long, ByVal iModeNum As Long, lptypDevMode As Any) As Boolean
Declare Function ChangeDisplaySettings Lib "user32" Alias "ChangeDisplaySettingsA" (lptypDevMode As Any, ByVal dwFlags As Long) As Long
Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, ByVal dwReserved As Long) As Long
VBcoders
Dim lngResult As Long
Dim intAns As Integer
' Retrieve info about the current graphics mode
' on the current display device.
lngResult = EnumDisplaySettings(0, 0, typDevM)
' Set the new resolution. Don't change the color
' depth so a restart is not necessary.
With typDevM
.dmFields = DM_PELSWIDTH Or DM_PELSHEIGHT
.dmPelsWidth = 640 'ScreenWidth (640,800,1024, etc)
.dmPelsHeight = 480 'ScreenHeight (480,600,768, etc)
End With
' Change the display settings to the specified graphics mode.
lngResult = ChangeDisplaySettings(typDevM, CDS_TEST)
Select Case lngResult
Case DISP_CHANGE_RESTART
intAns = MsgBox("You must restart your computer to apply these changes." & _
vbCrLf & vbCrLf & "Do you want to restart now?", _
vbYesNo + vbSystemModal, "Screen Resolution")
If intAns = vbYes Then Call ExitWindowsEx(EWX_REBOOT, 0)
Case DISP_CHANGE_SUCCESSFUL
Call ChangeDisplaySettings(typDevM, CDS_UPDATEREGISTRY)
MsgBox "Screen resolution changed", vbInformation, "Resolution Changed"
Case Else
MsgBox "Mode not supported", vbSystemModal, "Error"
End Select
