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