CreateProcess, using Visual Basic, doesn't create a process

Question

I'm having difficulties with using CreateProcess in Visual Basic. The purpose is to open NotePad in a particular place on the screen and with a specific size. This the code I am using so far (after many errors & tests):

Structure SECURITY_ATTRIBUTES
	Dim nLength As Integer
	Dim lpSecurityDescriptor As IntPtr
End Structure

Enum CreationFlags
	CreateSuspended = &H4
	DetachedProcess = &H8
	CreateNoWindow = &H8000000
	ExtendedStartupInfoPresent = &H80000
End Enum

Structure STARTUPINFO
	Dim cb As Integer
	Dim lpReserved As String
	Dim lpDesktop As String
	Dim lpTitle As String
	Dim dwX As Integer
	Dim dwY As Integer
	Dim dwXSize As Integer
	Dim dwYSize As Integer
	Dim dwXCountChars As Integer
	Dim dwYCountChars As Integer
	Dim dwFillAttributes As Integer
	Dim dwFlags As Integer
	Dim wShowWindow As Integer
	Dim cbReserved As Integer
	Dim lpReserved2 As Integer
	Dim hStdInput As Integer
	Dim hStdOutput As Integer
	Dim hStdErr As Integer
End Structure

Structure STARTUPINFOEX
	Dim StartupInfo As STARTUPINFO
	Dim lpAttributeList As IntPtr
End Structure

Structure PROCESS_INFORMATION
	Dim hProcess As IntPtr
	Dim hThread As IntPtr
	Dim dwProcessId As Integer
	Dim dwThreadId As Integer
End Structure

Const EXTENDED_STARTUPINFO_PRESENT As UInteger = &H80000

Const STARTF_USEPOSITION = &H4          ' The dwX & dwY members contain additional information.
Const STARTF_USESHOWWINDOW = &H1        ' The wShowWindow member contains additional information.
Const STARTF_USESIZE = &H2              ' The dwXSize & dwYSize members contain additional information.

<DllImport("kernel32.dll", SetLastError:=True)>
Shared Function CreateProcess(lpApplicationName As String,
							  lpCommandLine As String,
							  ByRef lpProcessAttributes As SECURITY_ATTRIBUTES,
							  ByRef lpThreadAttributes As SECURITY_ATTRIBUTES,
							  bInheritHandles As Boolean,
							  dwCreationFlags As UInt32,
							  lpEnvironment As IntPtr,
							  lpCurrentDirectory As String,
							  ByRef lpStartupInfo As STARTUPINFO,
							  ByRef lpProcessInformation As PROCESS_INFORMATION) As Boolean
End Function

Friend Shared Sub StartupNotepad()

	Dim retValue As Boolean
	Dim Application As String = "notepad"
	Dim CommandLine As String = ""
	Dim pInfo As PROCESS_INFORMATION = New PROCESS_INFORMATION()
	Dim sInfo As STARTUPINFO = New STARTUPINFO()
	Dim pSec As SECURITY_ATTRIBUTES = New SECURITY_ATTRIBUTES()
	Dim tSec As SECURITY_ATTRIBUTES = New SECURITY_ATTRIBUTES()
	pSec.nLength = pSec.lpSecurityDescriptor.ToInt32
	tSec.nLength = tSec.lpSecurityDescriptor.ToInt32
	Dim CreationFlags As UInt32 = EXTENDED_STARTUPINFO_PRESENT
	Dim Environ As IntPtr
	Dim ThisDir As String = Environment.CurrentDirectory
	sInfo.dwX = 10
	sInfo.dwY = 10
	sInfo.dwXSize = 100
	sInfo.dwYSize = 400
	sInfo.dwFlags = STARTF_USEPOSITION + STARTF_USESIZE + STARTF_USESHOWWINDOW
	sInfo.lpReserved = ""
	sInfo.cb = Len(sInfo)

	retValue = CreateProcess(Application, CommandLine, pSec, tSec, False, CreationFlags, Environ, vbNull, sInfo, pInfo)

End Sub

I don't appear to be getting any error messages but retValue returns false every time and no new NotePad window appears when I call StartupNotepad. Any clues as to what I am (clearly) doing wrong would be appreciated.

Answer 1

This test works for me (except position/size, read from registry for Notepad as I commented...) :

        Dim pSec As SECURITY_ATTRIBUTES = New SECURITY_ATTRIBUTES()
        Dim tSec As SECURITY_ATTRIBUTES = New SECURITY_ATTRIBUTES()
        pSec.nLength = Marshal.SizeOf(pSec)
        tSec.nLength = Marshal.SizeOf(tSec)
        'Dim sApplicationName = "C:\WINDOWS\system32\notepad.exe"
        Dim sApplicationName = Nothing
        Dim sCommandLine = "notepad.exe"
        Dim nCreationFlags = NORMAL_PRIORITY_CLASS
        Dim sInfo As STARTUPINFO = New STARTUPINFO()
        sInfo.cb = Marshal.SizeOf(sInfo)
        sInfo.dwFlags = STARTF_USEPOSITION Or STARTF_USESIZE Or STARTF_USESHOWWINDOW
        sInfo.wShowWindow = SW_SHOWNORMAL
        ' Ignored : read from HKEY_CURRENT_USER\SOFTWARE\Microsoft\Notepad
        sInfo.dwX = 10
        sInfo.dwY = 10
        sInfo.dwXSize = 100
        sInfo.dwYSize = 400
        Dim pInfo As PROCESS_INFORMATION = New PROCESS_INFORMATION()
        Dim bRet = CreateProcess(sApplicationName, sCommandLine, pSec, tSec, False, nCreationFlags, IntPtr.Zero, Nothing, sInfo, pInfo)
        If (Not bRet) Then
            Dim nErr = Marshal.GetLastWin32Error()
            ' ...
        End If

With :

   <DllImport("Kernel32.dll", CharSet:=CharSet.Unicode, SetLastError:=True)>
    Public Shared Function CreateProcess(lpApplicationName As String, lpCommandLine As String, ByRef lpProcessAttributes As SECURITY_ATTRIBUTES,
                                         ByRef lpThreadAttributes As SECURITY_ATTRIBUTES, bInheritHandles As Boolean, dwCreationFlags As UInteger,
                                         lpEnvironment As IntPtr, lpCurrentDirectory As String,
                                         <[In]> ByRef lpStartupInfo As STARTUPINFO, <Out> ByRef lpProcessInformation As PROCESS_INFORMATION) As Boolean
    End Function


    <StructLayout(LayoutKind.Sequential)>
    Public Structure SECURITY_ATTRIBUTES
        Public nLength As Integer
        Public lpSecurityDescriptor As IntPtr
        Public bInheritHandle As Integer
    End Structure

    <StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
    Public Structure STARTUPINFO
        Public cb As Integer
        Public lpReserved As String
        Public lpDesktop As String
        Public lpTitle As String
        Public dwX As Integer
        Public dwY As Integer
        Public dwXSize As Integer
        Public dwYSize As Integer
        Public dwXCountChars As Integer
        Public dwYCountChars As Integer
        Public dwFillAttribute As Integer
        Public dwFlags As Integer
        Public wShowWindow As Short
        Public cbReserved2 As Short
        Public lpReserved2 As IntPtr
        Public hStdInput As IntPtr
        Public hStdOutput As IntPtr
        Public hStdError As IntPtr
    End Structure

    <StructLayout(LayoutKind.Sequential)>
    Public Structure PROCESS_INFORMATION
        Public hProcess As IntPtr
        Public hThread As IntPtr
        Public dwProcessId As Integer
        Public dwThreadId As Integer
    End Structure

    Public Const NORMAL_PRIORITY_CLASS = &H20

    Public Const STARTF_USESHOWWINDOW = &H1
    Public Const STARTF_USESIZE = &H2
    Public Const STARTF_USEPOSITION = &H4
    Public Const STARTF_USECOUNTCHARS = &H8
    Public Const STARTF_USEFILLATTRIBUTE = &H10
    Public Const STARTF_RUNFULLSCREEN = &H20  ' ignored for non-x86 platforms
    Public Const STARTF_FORCEONFEEDBACK = &H40
    Public Const STARTF_FORCEOFFFEEDBACK = &H80
    Public Const STARTF_USESTDHANDLES = &H100
    Public Const STARTF_USEHOTKEY = &H200
    Public Const STARTF_TITLEISLINKNAME = &H800
    Public Const STARTF_TITLEISAPPID = &H1000
    Public Const STARTF_PREVENTPINNING = &H2000
    Public Const STARTF_UNTRUSTEDSOURCE = &H8000

    Public Const SW_SHOWNORMAL = 1