When to use OpenWeb() vs RootWeb

Question

I am a little confused on the pro's and con's of each. When is it good to use OpenWeb() vs RootWeb, especially in the context of a using statement.

Answer 1

You would never use RootWeb in the context of a using statement and OpenWeb() isn't useful unless the URL specified in the SPSite constructor was a sub web of the site collection in lieu of just the site collection URL.

So, you should never do this:

using (SPWeb web = site.RootWeb)
{
    // do something with web
}

...and OpenWeb() is useful in a scenario like this:

using (SPSite site = new SPSite("http://sharepointdev/subsite"))
{
    // RootWeb would return the http://sharepointdev and OpenWeb() would return "subsite"
    using (SPWeb web = site.OpenWeb())
    { 
        // do something with web
    }
}

...but OpenWeb() doesn't do anything in this scenario, except create an extra SPWeb object...use RootWeb:

using (SPSite site = new SPSite("http://sharepointdev"))
{
   // do something with site.RootWeb
}

Answer 2

If you want to get hold of a subsite using GUID or URL (server-relative or site-relative), OpenWeb() should be used.The SPWeb returned from OpenWeb() should be manually disposed. Also, want to share this for something interesing on OpenWeb() .

RootWeb gives you the top most SPWeb associated with SPSite. Although, you can also get it using OpenWeb(), RootWeb is preferred as it does not require explicit disposal of SPWeb object it provides.