I had a program developed in C# VS2010 and VS2005. The program still works just fine on all Window OSs from Win 2000->XP->Windows 7. All 32 bit versions. The problem came when this program runs on 64 bit Windows7. The program fails during
the call to LoadLibrary(). Used P/Invoke method to use this function. The LoadLibrary fails with
any dll and not only the one I want. My project settings are "built on x86" and the Target Platform as "Any CPU". Infact I tried a small program(thinking that My original program is buggy), a windows forms application with two buttons.
One Button will use LoadLibrary() and one for FreeLibrary(). Same issue on 64 bit. The LoadLibrary fails with error code 193. used same P/Invoke method for making use of the native kernel32.dll in the System32 folder. Can anyone point
me if I need to do anything additonal for the program to work. I am using the C# VS2010 for development and still has to use .Net 2.0. Any suggestion is greatly appreciated.
Thanks.
Here is my code:
using
using
using
using
using
using
using
using
using
using
using
namespace
{
{
public
Form1() public
class
UnManagedCodeB
{
InitializeComponent();
}
{
#region
Kernel32 DLL Import Functions
arSet =
CharSet.Auto,
BestFitMapping = false,
SetLastError = true)]
public
static
extern
IntPtr
LoadLibrary(string
lpFilename);
[
[
[
[
[
#endregion
}
{
m_DllHandle =
{
{error_code =
M
}
}
{
error_code = U
}
}
{
}
nManagedCodeB.GetLastError();
MessageBox.Show(error_code.ToString(),
"Dll Handle Return code");
Application.Exit();
private
void
button3_Click(object
sender, EventArgs
e) UnManagedCodeB.FreeLibrary(m_DllHandle);
}
catch
(Exception
x) MessageBox.Show(x.Message,
"DLL Loading problem(LoadUSBLibrary())!");if
(m_DllHandle == IntPtr.Zero)
UnManagedCodeB.GetLastError();
essageBox.Show(error_code.ToString(),
"Dll load failed(LoadLibrary()");
throw
new
ApplicationException("Error
loading " + filename.ToString());private
IntPtr
m_DllHandle;
private
void
button1_Click(object
sender, EventArgs
e) int
error_code ;
string
filename = "C:\\Windows\\SysWOW64\\UAUSBIP.dll";
UnManagedCodeB.LoadLibrary(
filename);
trypublic
static
extern
int
GetLastError();DllImport("C:\\Windows\\System32\\kernel32.dll",
CharSet = CharSet.Ansi,
ExactSpelling = true)]
public
static
extern
IntPtr
GetProcAddress(IntPtr
hModule, string
procName);
DllImport("C:\\Windows\\System32\\kernel32.dll")]
public
static
extern
bool
FreeLibrary(IntPtr
hModule);
DllImport("C:\\Windows\\System32\\kernel32.dll")]
public
static
extern
bool
SetDllDirectory(string
path);
DllImport("C:\\Windows\\System32\\kernel32.dll",
SetLastError = true)]
public
static
extern
void
SetLastError(int
errorCode);
DllImport("C:\\Windows\\System32\\kernel32.dll")][DllImport("C:\\Windows\\System32\\kernel32.dll",
ChCS_64bit_TestApp
public
partial
class
Form1
: FormSystem.Windows.Forms;System.Runtime.InteropServices;System.Threading;System.IO.Ports;System.IO;System.Text;System.Drawing;System.Data;System.ComponentModel;System.Collections.Generic;System;
