Question

Given the SPList.ID and a site collection (or an SPWeb with subwebs), how do I quickly find the document library with the given ID?

I can recursively enumerate through all webs and perform a web.Lists[guid] on each one of them, but there might be thousands of subwebs in my case, and I’m looking for a realtime solution.

If there is no way to do this quickly, any other suggestions on how to uniquely identify a document library? I could store the full path (url), but the identification will be publicly visible and I don’t feel very comfortable giving away our exact SharePoint document structure like that. Should I resort to maintaining a manual ID <-> library mapping in a separate list?

Answer 1

Since you are storing the ListID somewhere, you may also store the WebId. Lists are opened by the context SPWeb always, so if you go to:

http://toplevel/_layouts/ListGeneralSettings.aspx?ID={GUID1} // OK
http://toplevel/sub1/_layouts/ListGeneralSettings.aspx?ID={GUID1} // Wont Work (same Guid)

Having the WebId and ListId you can simply:

using(SPWeb subweb = (new SPSite("http://url")).OpenWeb(new Guid("{000...}")))
{
    SPList list = subweb.Lists.GetList(new Guid("{111...}"), true);
    // list logic
}