Hi All,

I have an Excel application in which I change the resolution on entr
if the resolution is less than 1024 X768. The application consists of
different workbooks, on exit I want to restore the original settings.

I have been successfully changing the resolution but I cannot seem t
return the original settings when I dynamically set the resolution.

I was under the impression that when I used the flag 0& I was changin
the resolution dynamically & it was not written to the registry.

Call ChangeDisplaySettings(DevM, 0&)

And when I used the Null as the mode the original settings in th
registry would be restored.

Call ChangeDisplaySettings(vbNullString, 0&)

Has anyone had any experience with this? The application will b
running Office 2000 & upwards (OS Win95- WindowsXP).

I know it is not good practice to change users display settings but a
this stage I have to use this method.

Thanks,
Adam.

Private Declare Function EnumDisplaySettings Lib "user32" _
Alias "EnumDisplaySettingsA" _
(ByVal lpszDeviceName As Long, _
ByVal iModeNum As Long, _
lpDevMode As Any) As Boolean

Private Declare Function ChangeDisplaySettings Lib "user32" _
Alias "ChangeDisplaySettingsA" _
(lpDevMode As Any, _
ByVal dwFlags As Long) As Long

Private Type DEVMODE
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

Sub ChangeRes()
'Change resolution to 1024 X 768
Const CDS_UPDATEREGISTRY = &H1
Const CDS_TEST = &H4

Dim blnWorked As Boolean
Dim i As Long
Dim DevM As DEVMODE
i = 0
Do
blnWorked = EnumDisplaySettings(0&, i, DevM)
i = i + 1
Loop Until (blnWorked = False)

With DevM
.dmFields = DM_PELSWIDTH Or DM_PELSHEIGHT
.dmPelsWidth = 1024
.dmPelsHeight = 768
End With

'Update dynamically
Call ChangeDisplaySettings(DevM, 0&)

End Sub

Sub ReturnSettings()
'Return Settings
Call ChangeDisplaySettings(vbNullString, 0&)
End Sub



[b]:

--
Message posted from http://www.ExcelForum.com

Hi Adam,

Can't test it as my new LCD screen gets *very* unhappy with having its
resolution changed, but, for the reset, try changing it to:

ChangeDisplaySettings ByVal 0&, 0&

HTH

Peter Beach

"adam99 " wrote in message
...
Hi All,

I have an Excel application in which I change the resolution on entry
if the resolution is less than 1024 X768. The application consists of 7
different workbooks, on exit I want to restore the original settings.

I have been successfully changing the resolution but I cannot seem to
return the original settings when I dynamically set the resolution.

I was under the impression that when I used the flag 0& I was changing
the resolution dynamically & it was not written to the registry.

Call ChangeDisplaySettings(DevM, 0&)

And when I used the Null as the mode the original settings in the
registry would be restored.

Call ChangeDisplaySettings(vbNullString, 0&)

Has anyone had any experience with this? The application will be
running Office 2000 & upwards (OS Win95- WindowsXP).

I know it is not good practice to change users display settings but at
this stage I have to use this method.

Thanks,
Adam.

Private Declare Function EnumDisplaySettings Lib "user32" _
Alias "EnumDisplaySettingsA" _
(ByVal lpszDeviceName As Long, _
ByVal iModeNum As Long, _
lpDevMode As Any) As Boolean

Private Declare Function ChangeDisplaySettings Lib "user32" _
Alias "ChangeDisplaySettingsA" _
(lpDevMode As Any, _
ByVal dwFlags As Long) As Long

Private Type DEVMODE
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

Sub ChangeRes()
'Change resolution to 1024 X 768
Const CDS_UPDATEREGISTRY = &H1
Const CDS_TEST = &H4

Dim blnWorked As Boolean
Dim i As Long
Dim DevM As DEVMODE
i = 0
Do
blnWorked = EnumDisplaySettings(0&, i, DevM)
i = i + 1
Loop Until (blnWorked = False)

With DevM
dmFields = DM_PELSWIDTH Or DM_PELSHEIGHT
dmPelsWidth = 1024
dmPelsHeight = 768
End With

'Update dynamically
Call ChangeDisplaySettings(DevM, 0&)

End Sub

Sub ReturnSettings()
'Return Settings
Call ChangeDisplaySettings(vbNullString, 0&)
End Sub



[b]:)


---
Message posted from http://www.ExcelForum.com/

Thanks for replying Peter, it works well on my PC(further testing o
other OS will be required). I really don't like changing the scree
resolutioin but at the moment I can't get around it. I will have to pu
some error handling for situations where reboots are required & thos
similair to your LCD monitor.

Thanks Again,
Adam.:

--
Message posted from http://www.ExcelForum.com

Hi Adam,

Glad the solution passed the first hurdle <g.

Just to explain the difference. The API wizard, accurately, defines the
function as:

Private Declare Function ChangeDisplaySettings Lib "user32" _
Alias "ChangeDisplaySettingsA" _
(lpDevMode As Any, _
ByVal dwFlags As Long) As Long

The first parameter is passed by reference (i.e. a pointer in C parlance).
API calls are treated by the O/S using C language. In C Null is the *value*
0. When you pass in 0& (unqualified), which is what vbNullString evaluates
to, you are telling the O/S to reference the memory at address 0 (sadly this
is the start of the O/S memory and unless your computer is in a sad state
its value will not be zero!). By changing the call to ByVal 0& you
overwrite the function declaration and tell the O/S to use the value 0 which
is correctly interpreted as Null.

Best wishes,

Peter Beach

"adam99 " wrote in message
...
Thanks for replying Peter, it works well on my PC(further testing on
other OS will be required). I really don't like changing the screen
resolutioin but at the moment I can't get around it. I will have to put
some error handling for situations where reboots are required & those
similair to your LCD monitor.

Thanks Again,
Adam.:)


---
Message posted from http://www.ExcelForum.com/