Accessing CreateProcess from C# and VB.NET

I came across this issue recently. I was trying to access CreateProcess using DLLImport from managed code using C# and VB.Net. Here is my code from C#:

 

using System;

using System.Diagnostics;

using System.Runtime.InteropServices;

public struct PROCESS_INFORMATION

{

    public IntPtr hProcess;

    public IntPtr hThread;

    public uint dwProcessId;

    public uint dwThreadId;

}

public struct STARTUPINFO

{

    public uint cb;

    public string lpReserved;

    public string lpDesktop;

    public string lpTitle;

    public uint dwX;

    public uint dwY;

    public uint dwXSize;

    public uint dwYSize;

    public uint dwXCountChars;

    public uint dwYCountChars;

    public uint dwFillAttribute;

    public uint dwFlags;

    public short wShowWindow;

    public short cbReserved2;

    public IntPtr lpReserved2;

    public IntPtr hStdInput;

    public IntPtr hStdOutput;

    public IntPtr hStdError;

}

public struct SECURITY_ATTRIBUTES

{

    public int length;

    public IntPtr lpSecurityDescriptor;

    public bool bInheritHandle;

}

public class Program

{

    public static void Main()

    {

        STARTUPINFO si = new STARTUPINFO();

        PROCESS_INFORMATION pi = new PROCESS_INFORMATION();

        CreateProcess("C:\\WINDOWS\\SYSTEM32\\Calc.exe", null, IntPtr.Zero, IntPtr.Zero, false, 0, IntPtr.Zero, null, ref si, out pi);

        Console.ReadLine();

    }

[DllImport("kernel32.dll")]

static extern bool CreateProcess(string lpApplicationName, string lpCommandLine, IntPtr lpProcessAttributes, IntPtr lpThreadAttributes,

                        bool bInheritHandles, uint dwCreationFlags, IntPtr lpEnvironment,

                        string lpCurrentDirectory, ref STARTUPINFO lpStartupInfo,out PROCESS_INFORMATION lpProcessInformation);

}

 

 

This works like a charm. I initially had problems with this VB code. I looked at the IL code for both and figured out that I had constructed structures in C# for Process_Information, Security_Attricutes etc, but had marked them as classes in VB. This was mking the call to fail. I figured this out after looking into the IL from VB and C# to see what was different between the two. I changed the VB to struct and it works like a charm in VB too. Check the VB code below!

 

 

Imports System.Runtime.InteropServices

Imports System.Security.Permissions

Imports System.Reflection

Module Module1

Sub Main()

StartupNotepad()

Console.ReadLine()

End Sub

Sub StartupNotepad()

Dim retValue As Boolean

Dim pInfo As PROCESS_INFORMATION = New PROCESS_INFORMATION()

Dim sInfo As STARTUPINFO = New STARTUPINFO()

retValue = CreateProcess("c:\\windows\\system32\\NotePad.exe", Nothing, IntPtr.Zero, IntPtr.Zero, False, 0, IntPtr.Zero, Nothing, sInfo, pInfo)

End Sub

<StructLayout(LayoutKind.Sequential)> _

Public Structure PROCESS_INFORMATION

Public hProcess As IntPtr

Public hThread As IntPtr

Public dwProcessID As UInteger

Public dwThreadID As UInteger

End Structure 'PROCESS_INFORMATION

<StructLayout(LayoutKind.Sequential)> _

Public Structure SECURITY_ATTRIBUTES

Public nLength As Integer

Public lpSecurityDescriptor As IntPtr

Public bInheritHandle As Boolean

End Structure 'SECURITY_ATTRIBUTES

<StructLayout(LayoutKind.Sequential)> _

Public Structure STARTUPINFO

Public cb As UInteger

Public lpReserved As String

Public lpDesktop As String

Public lpTitle As String

Public dwX As UInteger

Public dwY As UInteger

Public dwXSize As UInteger

Public dwYSize As UInteger

Public dwXCountChars As UInteger

Public dwYCountChars As UInteger

Public dwFillAttribute As UInteger

Public dwFlags As UInteger

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 'STARTINFO

<DllImport("kernel32.dll")> _

Function CreateProcess( _

ByVal lpApplicationName As String, _

ByVal lpCommandLine As String, _

ByVal lpProcessAttributes As IntPtr, _

ByVal lpThreadAttributes As IntPtr, _

ByVal bInheritHandles As Boolean, _

ByVal dwCreationFlags As UInteger, _

ByVal lpEnvironment As IntPtr, _

ByVal lpCurrentDirectory As String, _

ByRef lpStartupInfo As STARTUPINFO, _

ByRef lpProcessInformation As PROCESS_INFORMATION) As Boolean

End Function

End Module