Why does this vb.net code fail?

  • Thread starter Thread starter jim
  • Start date Start date
J

jim

VB.net code to turn monitor on and off.......

<CODE>
Module Module1
Const HWND_BROADCAST As Integer = &HFFFF
Const SC_MONITORPOWER As Integer = &HF170
Const WM_SYSCOMMAND As Short = &H112S

Sub Main()
Dim instr As String = Command()
Select Case Command().ToLower
'Make sure it matches - and look at the commandline switch
Case "off"
TurnOff()
Case "on"
TurnOn()
Case "test"
TurnOff()
'turn off monitor
System.Threading.Thread.Sleep(10000)
'wait 10 seconds
TurnOn()
'turn on monitor
Case Else
MsgBox("Usage, [on]/[off]/[test] ", _
MsgBoxStyle.Information, _
"Need Command Switch")
End Select
End Sub

Private Function SendMessage(ByVal Handle As Int32, _
ByVal wMsg As Int32, ByVal wParam As Int32, _
ByVal lParam As Int32) As Int32

End Function

Sub StandBy()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, 1)
End Sub

Sub TurnOff()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, 2)
End Sub

Sub TurnOn()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, -1)
End Sub

End Module
</CODE>

According to the author (http://www.codeproject.com/useritems/Monitors.asp)
the code is supposed to allow you to turn off the monitor but it has no
effect at all on my XP Pro SP2 fully patched PC with LCD screen.

Any clues?
 
jim said:
VB.net code to turn monitor on and off.......

<CODE>
Module Module1
Const HWND_BROADCAST As Integer = &HFFFF
Const SC_MONITORPOWER As Integer = &HF170
Const WM_SYSCOMMAND As Short = &H112S

Sub Main()
Dim instr As String = Command()
Select Case Command().ToLower
'Make sure it matches - and look at the commandline
switch Case "off"
TurnOff()
Case "on"
TurnOn()
Case "test"
TurnOff()
'turn off monitor
System.Threading.Thread.Sleep(10000)
'wait 10 seconds
TurnOn()
'turn on monitor
Case Else
MsgBox("Usage, [on]/[off]/[test] ", _
MsgBoxStyle.Information, _
"Need Command Switch")
End Select
End Sub

Private Function SendMessage(ByVal Handle As Int32, _
ByVal wMsg As Int32, ByVal wParam As Int32, _
ByVal lParam As Int32) As Int32

End Function

Sub StandBy()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER,
1) End Sub

Sub TurnOff()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER,
2) End Sub

Sub TurnOn()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER,
-1) End Sub

End Module
</CODE>

According to the author
(http://www.codeproject.com/useritems/Monitors.asp) the code is
supposed to allow you to turn off the monitor but it has no effect
at all on my XP Pro SP2 fully patched PC with LCD screen.

Any clues?
Click to expand...


Your Funcstion SendMessage does Nothing. It is empty. Get the right
declaration:

http://www.google.com/search?as_q=S...as_dt=i&as_sitesearch=&as_rights=&safe=images


Armin
 
VB.net code to turn monitor on and off.......
Click to expand...
<CODE>
Module Module1
Const HWND_BROADCAST As Integer = &HFFFF
Const SC_MONITORPOWER As Integer = &HF170
Const WM_SYSCOMMAND As Short = &H112S
Click to expand...
Sub Main()
Dim instr As String = Command()
Select Case Command().ToLower
'Make sure it matches - and look at the commandline
switch Case "off"
TurnOff()
Case "on"
TurnOn()
Case "test"
TurnOff()
'turn off monitor
System.Threading.Thread.Sleep(10000)
'wait 10 seconds
TurnOn()
'turn on monitor
Case Else
MsgBox("Usage, [on]/[off]/[test] ", _
MsgBoxStyle.Information, _
"Need Command Switch")
End Select
End Sub
Click to expand...
Private Function SendMessage(ByVal Handle As Int32, _
ByVal wMsg As Int32, ByVal wParam As Int32, _
ByVal lParam As Int32) As Int32
Click to expand...
End Function
Click to expand...
Sub StandBy()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER,
1) End Sub
Click to expand...
Sub TurnOff()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER,
2) End Sub
Click to expand...
Sub TurnOn()
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER,
-1) End Sub
Click to expand...
End Module
</CODE>
Click to expand...
According to the author
(http://www.codeproject.com/useritems/Monitors.asp) the code is
supposed to allow you to turn off the monitor but it has no effect
at all on my XP Pro SP2 fully patched PC with LCD screen.
Click to expand...
Any clues?
Click to expand...

Your Funcstion SendMessage does Nothing. It is empty. Get the right
declaration:

http://www.google.com/search?as_q=SendMessage+declare+function+intptr...

Armin
Click to expand...

Or check pinvoke.net for the correct declaration:

http://www.pinvoke.net/default.aspx/user32/SendMessage.html

Thanks,

Seth Rowe
 
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