Decompile Dll - Code has CS$4$0001 for vars

Question

I want to edit a dll file if possible or extract the contents and modify them.

I have used .Net Reflector to decompile and generate files.

That worked great except some files have things like CS$4$0001 instead of variables.

also <>g__initLocal31

Is there a way to find what those are? Or Should I just replace all instances, and test?

ADDED:

    [OutputCache(NoStore=true, Location=OutputCacheLocation.Client, Duration=1)]
    public ActionResult _StateTile(string AssetName, string StateName)
    {
        aaReportsEntities dataContext;
        string CS$4$0001 = StateName;
        if (CS$4$0001 != null)
        {
            if (!(CS$4$0001 == "IDLE-UPSTREAM"))

Answer 1

Those can be:

• local variables (don't have names in IL)
• backing fields for automatically implemented properties / field-like events
• fields for anything compiler-generated (capture-context related scopes, etc)
• expression-tree / delegate caches
• "dynamic" caches
• state variables in iterator-blocks / "await" code
• etc (again, mainly anything compiler-generated)

They are important. But frankly, you probably shouldn't be extracting code via reflector: usually, if you have justification in doing that, you already own the source code (or are licensed to access it)

Answer 2

You cant get variable names back. TReverse engineering is very difficult to do, recommend this book - http://www.amazon.co.uk/Reversing-Secrets-Engineering-Eldad-Eilam/dp/0764574817/ref=sr_1_1?ie=UTF8&qid=1353436851&sr=8-1