Hi Ian
Thanks for the Code Project link. It looks really great.
I searched CodeProject and did not find this page.
I am fairly certain I have MS Access using my C# COM aware dll.
I have tested it and it works great.
To morrow I will pass it over to the the person who supports Access at
our site.
Personally I can't stand Access but they needed a function they could
call from VBA to protect passwords that they
store in a database table. I though a hash would be easier than a
symmetric cipher. I tend to shy away using reversible symmetric ciphers
within insecure code. It is just too easy to bypass most of the security
features in Access.
Its really just a one off to try and make their access front end
applications a bit more secure.
Regards Peter.
On 8/03/2010 3:33 PM, Ian Thomas wrote:
Peter
Did you try the sample code, with Excel? The GUID in the C# or Vb.NET
will be different for Excel, Access.
Have a read of this article (CodeProject) for an overview -
http://www.codeproject.com/KB/COM/cominterop.aspx
------------------------------------------------------------------------
Ian Thomas
Victoria Park, Western Australia
------------------------------------------------------------------------
*From:* [email protected]
[mailto:[email protected]] *On Behalf Of *Maddin, Peter
*Sent:* Monday, 8 March 2010 2:34 PM
*To:* ozDotNet
*Subject:* RE: Calling a class library C# method from ms access
Thanks Ian
I ma having trouble translating this from Vb.NET to C#.
I built the class library and then used reflector to see the c# code.
Tried cutting and pasting but the VS Editor did not like it.
Googling other material, locates code that only vaguely resembles that
in your link below.
I am venturing into unchartered territory never having had much to
with Com before (and being told it was dead)
The latest one has no GUIDs at all
http://www.codeproject.com/KB/office/ParallelMsAccess.aspx
My project is tiny
using System;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
using System.Text;
namespace PathWest
{
[ComVisible(true)]
public interface HashInterface
{
string Md5Hash(string passwordValue);
}
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.None)]
public class GetHash : HashInterface
{
public string Md5Hash(string passwordValue)
{
byte[] hashValue = new
MD5CryptoServiceProvider().ComputeHash(Encoding.ASCII.GetBytes(passwordValue));
return Encoding.ASCII.GetString(hashValue);
}
}
}
I do see one in the Assembly.cs file though
// Setting ComVisible to false makes the types in this assembly not
visible
// to COM components. If you need to access a type in this assembly from
// COM, set the ComVisible attribute to true on that type.
[assembly: ComVisible(true)]
// The following GUID is for the ID of the typelib if this project is
exposed to COM
[assembly: Guid("b92f832a-3887-412b-a126-e58f35041f2d")]
*Regards Peter Maddin*
*Applications Development Officer*
*Path**West Laboratory Medicine WA*
*Phone : +618 9473 3944*
*Fax : +618 9473 3982*
*E-Mail : [email protected]*
*The contents of this e-mail transmission outside of the WAGHS network
are intended solely for the named recipient's), may be confidential,
and may be privileged or otherwise protected from disclosure in the
public interest. The use, reproduction, disclosure or distribution of
the contents of this e-mail transmission by any person other than the
named recipient(s) is prohibited. If you are not a named recipient
please notify the sender immediately.*
*From:* [email protected]
[mailto:[email protected]] *On Behalf Of *Ian Thomas
*Sent:* Monday, 8 March 2010 11:13 AM
*To:* 'ozDotNet'
*Subject:* RE: Calling a class library C# method from ms access
http://support.microsoft.com/kb/317535
------------------------------------------------------------------------
Ian Thomas
Victoria Park, Western Australia
------------------------------------------------------------------------
*From:* [email protected]
[mailto:[email protected]] *On Behalf Of *Maddin, Peter
*Sent:* Monday, 8 March 2010 10:49 AM
*To:* [email protected]
*Subject:* Calling a class library C# method from ms access
I need to call a C# method from MS Access 2003.
I need to pass in a string and return a string.
I have spent some trying to do this in Delphi but am now sure I need
to use COM so I might as well use C#.
I have wasted a couple of days almost getting it working only to find
that it was too flaky with Access crashing.
Does anyone have a simple code example they would be willing to share?
The goal is to pass in a string (which will be a password) and return
a hash of that string using MD5 or something similar.
Generating the hash is no problem its just writing the class and
method so Access will be able to call it, setting up the MS Access
declaration and calling the method passing in a string and returning a
string.
I believe one needs to make the assembly 'Com-Visible".
Also the Access declaration needs to specify the TLB and not the dll.
One needs to register the dll (? And tlb) using regasm.
Is there anything else required?
*Regards Peter Maddin*
*Applications Development Officer*
*Path**West Laboratory Medicine WA*
*Phone : +618 9473 3944*
*Fax : +618 9473 3982*
*E-Mail : [email protected]*
*The contents of this e-mail transmission outside of the WAGHS network
are intended solely for the named recipient's), may be confidential,
and may be privileged or otherwise protected from disclosure in the
public interest. The use, reproduction, disclosure or distribution of
the contents of this e-mail transmission by any person other than the
named recipient(s) is prohibited. If you are not a named recipient
please notify the sender immediately.*
