Question

How can i check if COM Object exists (is registered / is available / can run without problems) before running actions using them?

My application should use other applications COM’s (InteropServices) but before i start some action, i would like to check whether i can create COM objects.

It woudnt be a problem if COM’s where in same directory, but they’re not.

In excample.
I would like to check if sth like this:

CDNBase.ApplicationClass App = new CDNBase.ApplicationClass();

will cause catchable exceptions or something. Than i could create nice MessageBox and block some events till it will be fixed.
Any other solutions like checking if namespace exists or sth, are also ok (i guess 😀 )

I tried to use try / catch, but it fails, google didnt bring me anything special on this, so im asking for your help.

Thanks in advance

Answer 1

Have you tried catching ComException:

try
{
...
}
catch(System.Runtime.InteropServices.COMException ex)
{
    // log error message
    throw;
}

UPDATE: apologies, I wasn’t suggesting to suppress the exception. Have updated.

Alternatively, you could search in the registry for the component’s ClassID:

HKEY_CLASSES_ROOT\CLSID\{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}\InprocServer32 

The default value will contain the filesystem full path to the DLL.