Where does my .net assembly read its configuration from when hosted as COM?

Question

Ok i created a .net assembly and it works fine from my asp.net website. I now want to host it as COM, so i can use it on an old legacy asp website. It kinda works, except it won't read the appsettings from the configuration file.

I would think it should read it from the same folder where i registered my assembly with regasm and where the .dll resides. I tried copying the config file to two extra files (in case it read from a different named file besides "assembly-file-name"+.config The two files are app.config and application.config - it doesn't seem to read from any of them.

Where does my .net assembly read its configuration from when hosted as COM?

Answer 1

Sombody correct me if I'm wrong, but I don't think a DLL reads a config file at all. Even though you technically can create a config file for DLL projects as well (using the project properties), I don't think you're supposed to configure a DLL like that and I don't think the framework supports that.

There are two ways now:

1. Have the caller pass respective settings values to the objects as parameters
2. Build a method that reads the settings itself and call the method after creating the object.

EDIT
To check, you should name the config file application-name.config.xml, like for a WebForms application. But as I said, I doubt that it'll work...

Answer 2

Ok i found a solution that makes me happy.

I ended up hosting the COM object in Component Services. On the package i picked Properties and selected the Activation tab, there i entered the location of my config file in "Application Root Directory". Now to make it work, i had to rename my config file to application.config and somehow i also had to create a new file in the same location called application.manifest with the following data:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
</assembly>

This actually solves the problem of having "the dll" read the config file - actually since component services is the host (in place of the exe/website) it determines the location/config.

Woop - and thanks for the input guys - i hadn't thought of the problem Thorsten mentioned before.

Answer 3

If by COM you mean a COM application, then you should put your configuration in a file named after the EXE. YourApp.Exe -> YourApp.exe.config

If by COM you mean COM+, then take a look at http://blogs.msdn.com/heikkiri/archive/2005/11/10/491568.aspx