Registration-Free COM for standalone VB.NET application - complex case - vb.net

Question

I need your help.
I read whole internet about Registration-Free COM/DLLs but my problem is more complex.
I'm preparing an application in VB.NET which will be used in an environment in which users don't have admin rights, so I can't simpy install it or register COM. This COM is a LogParser library designed by microsoft.
DLL also doesn't have to be embeded - would be nice, but it may be also extracted from exe during startup - i'm ok with this approach
Generally in a main form i've got a button which invokes another form by:
LogParser_Form.Show()
This another Form 'Imports MSUtil', which is a Interop.MSUtil.dll and which is embeeded to exe by Fody Costura add-on.
Form contains also a class which has multiple declarations of variables defined in COM, eg:
Dim IISW3CLOG As New COMIISW3CInputContextClass
(there is more than one)
But this dll refers somewhere to bigger: LogParser.dll which is acutally a COM component which requires registration, so my LogParser_Form doesn't appear when button is clicked, but it throws an exception that COM component is not found...
Unfortunately Fody Costura or Ilmerge don't work for the COM...
I tried multiple tricks wich manifest files, etc, but no luck...
You are my last hope - please help me... How to embed this COM to exe without registering it?
I suppose that properly used manifest files may help, but I didn't find a way to successfully use it ...

Answer 1

Getting Registration-Free COM to work can be tricky, but works when configured properly. The key issue is creating manifests, which document all required dependencies. In your case, you'll need two manifests:
Client manifest for your application
Server manifest for the LogParser library. This part requires a tool for analyzing type libraries, such as the OLE/COM Object Viewer (oleview.exe). It allows looking into the embedded type library inside LogParser.dll.
Let's take the (slightly modified) C# example, which is documented in the LogParser help file. The client is named "logqryclient.exe" in this case, and the Runtime Callable Wrapper has been created via the type library importer (tlbimp).
using System;
using Interop.MSUtil;
namespace logqryclient
{
class Program
{
static void Main(string[] args)
{
try
{
// Instantiate the LogQuery object
ILogQuery oLogQuery = new LogQueryClassClass();
// Create the query
string query = #"SELECT TOP 50 SourceName, EventID, Message FROM System";
// Execute the query
ILogRecordset oRecordSet = oLogQuery.Execute(query, null);
// Browse the recordset
for (; !oRecordSet.atEnd(); oRecordSet.moveNext())
{
ILogRecord rec = oRecordSet.getRecord();
Console.WriteLine(rec.toNativeString(","));
}
// Close the recordset
oRecordSet.close();
}
catch (System.Runtime.InteropServices.COMException exc)
{
Console.WriteLine("Unexpected error: " + exc.Message);
}
}
}
}
To use this code without registering the COM classes, you'll first need to place the LogParser.dll into the same directory as the client executable.
Next, you'll need to create an accompanying server manifest (named "LogParser.manifest" here). This documents all necessary classes and marshalling information for the interfaces (required for thread switching). As mentioned earlier, you'll need a type library analyzer to gain access to the class and interface identifiers.
In the above case, you'll need identifiers for:
ILogQuery interface & LogQueryClass class
ILogRecordset interface
ILogRecord interface
Hence, the server manifest could look as follows:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity type="win32" name="LogParser" version="1.0.0.0" />
<file name = "LogParser.dll">
<!-- LogQueryClass -->
<comClass
clsid="{8CFEBA94-3FC2-45CA-B9A5-9EDACF704F66}"
threadingModel = "Apartment" />
<!-- Embedded type library -->
<typelib
tlbid="{A7E75D86-41CD-4B6E-B4BD-CC2ED34B3FB0}"
version="1.0"
helpdir=""/>
</file>
<!-- Marshalling information for interfaces -->
<comInterfaceExternalProxyStub
name="ILogQuery"
iid="{3BDE06BC-89E4-42FD-BE64-832A5F33D7D3}"
proxyStubClsid32="{00020424-0000-0000-C000-000000000046}"
baseInterface="{00000000-0000-0000-C000-000000000046}"
tlbid = "{A7E75D86-41CD-4B6E-B4BD-CC2ED34B3FB0}" />
<comInterfaceExternalProxyStub
name="ILogRecordset"
iid="{C9452B1B-093C-4842-ABD1-F81410926874}"
proxyStubClsid32="{00020424-0000-0000-C000-000000000046}"
baseInterface="{00000000-0000-0000-C000-000000000046}"
tlbid = "{A7E75D86-41CD-4B6E-B4BD-CC2ED34B3FB0}" />
<comInterfaceExternalProxyStub
name="ILogRecord"
iid="{185FFF88-E24A-4984-9621-AA41BEAE8513}"
proxyStubClsid32="{00020424-0000-0000-c000-000000000046}"
baseInterface="{00000000-0000-0000-c000-000000000046}"
tlbid = "{A7E75D86-41CD-4B6E-B4BD-CC2ED34B3FB0}" />
</assembly>
To allow the client to find the server manifest and ultimately the LogParser library, embed the following client manifest into the "logqryclient.exe" client:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity
type = "win32"
name = "logqryclient"
version = "1.0.0.0" />
<dependency>
<dependentAssembly>
<assemblyIdentity
type="win32"
name="LogParser"
version="1.0.0.0" />
</dependentAssembly>
</dependency>
</assembly>
Now, all required information is located in the manifests, so that you can run the code in registration-free configuration.