How to shut down...

[strider13]

Is there a way in Visual Basic to program a button to shut off the computer?



I have visual basic 2005 and 2008.

[Hack]

Moved to VB.NET

[.NetNinja]

Yes there is - but it is not that simple.

    Private Declare Function GetCurrentProcess Lib "kernel32.dll" () As IntPtr
    Private Declare Function OpenProcessToken Lib "advapi32.dll" (ByVal ProcessHandle As IntPtr, ByVal DesiredAccess As Int32, ByRef TokenHandle As IntPtr) As Int32
    Private Declare Function LookupPrivilegeValue Lib "advapi32.dll" Alias "LookupPrivilegeValueA" (ByVal lpSystemName As String, ByVal lpName As String, ByRef lpLuid As Luid) As Int32
    Private Declare Function AdjustTokenPrivileges Lib "advapi32.dll" (ByVal TokenHandle As IntPtr, ByVal DisableAllPrivileges As Int32, ByRef NewState As TOKEN_PRIVILEGES, ByVal BufferLength As Int32, ByRef PreviousState As TOKEN_PRIVILEGES, ByRef ReturnLength As Int32) As Int32
    Private Declare Function ExitWindowsEx Lib "user32.dll" (ByVal uFlags As Int32, ByVal dwReserved As Int32) As Int32

    Const SE_PRIVILEGE_ENABLED As Integer = &H2
    Const TOKEN_QUERY As Integer = &H8
    Const TOKEN_ADJUST_PRIVILEGES As Integer = &H20
    Const SE_SHUTDOWN_NAME As String = "SeShutdownPrivilege"

    Const EWX_LOGOFF As Integer = &H0
    Const EWX_SHUTDOWN As Integer = &H1
    Const EWX_REBOOT As Integer = &H2
    Const EWX_FORCE As Integer = &H4
    Const EWX_POWEROFF As Integer = &H8
    Const EWX_FORCEIFHUNG As Integer = &H10

    Public Structure LUID
        Dim LowPart As Int32
        Dim HighPart As Int32
    End Structure

    Public Structure TOKEN_PRIVILEGES
        Public PrivilegeCount As Integer
        Public Privileges As Luid
        Public Attributes As Int32
    End Structure

    Private Sub ShutDown()
            Dim platform As New PlatformID
            Select Case Environment.OSVersion.Platform
                Case PlatformID.Win32NT
                    Dim token As TOKEN_PRIVILEGES
                    Dim blank_token As TOKEN_PRIVILEGES
                    Dim token_handle As IntPtr
                    Dim uid As LUID
                    Dim ret_length As Integer
                    Dim ptr As IntPtr = GetCurrentProcess() '/// get the process handle

                    OpenProcessToken(ptr, &H20 Or &H8, token_handle)
                    LookupPrivilegeValue("", "SeShutdownPrivilege", uid)
                    token.PrivilegeCount = 1
                    token.Privileges = uid
                    token.Attributes = &H2

                    AdjustTokenPrivileges(token_handle, 0, token, System.Runtime.InteropServices.Marshal.SizeOf(blank_token), blank_token, ret_length)

                    ExitWindowsEx(EWX_SHUTDOWN Or EWX_FORCE, &HFFFF)

                Case Else
                    ExitWindowsEx(EWX_SHUTDOWN Or EWX_FORCE, &HFFFF)
            End Select
    End Sub

[dbasnett]

or

        'to stop shutdown
        'open a command window and enter
        'shutdown -a
        Dim extProc As ProcessStartInfo
        extProc = New ProcessStartInfo("shutdown", "-s -t 5")
        extProc.UseShellExecute = True
        System.Diagnostics.Process.Start(extProc)

[.NetNinja]

Yeah - you could do that too.

[jmcilhinney]

or

        'to stop shutdown
        'open a command window and enter
        'shutdown -a
        Dim extProc As ProcessStartInfo
        extProc = New ProcessStartInfo("shutdown", "-s -t 5")
        extProc.UseShellExecute = True
        System.Diagnostics.Process.Start(extProc)

Just one point to note here that isn't specifically on-topic. There's not much point setting UseShellExecute to True when you're executing an EXE file. The whole point of UseShellExecute is to get data files to open in their default application. If the file you specify is not a data file then UseShellExecute has no effect. The simplest way is just:

Process.Start("shutdown", "-s -t 5")

[dbasnett]

noted - it was a modify / test / copy / paste of something else.

[jmcilhinney]

I should also point out that UseShellExecute is True by default. You'd only set it to False if you were starting an EXE and wanted to redirect standard streams, i.e. stdin, stdout and stderror.