How do I get File Type Information based on extension? (not MIME) in c#

Question

How do I get the general File type description based on extension like Explorer does it? So not MIME but the information that the end-user sees, like.

.doc = Microso

Answer 1

Some extra if's for unknown file types in XP.. May not really give the right results when using it with anything but FriendlyDocName, but just as an example:

public static string FileExtentionInfo(AssocStr assocStr, string doctype)
{
   if ((doctype.Length <= 1) || !doctype.StartsWith(".")) return "";

   uint pcchOut = 0;
   AssocQueryString(AssocF.Verify, assocStr, doctype, null, null, ref pcchOut);

   if (pcchOut == 0) return (doctype.Trim('.').ToUpper() + " File");

   StringBuilder pszOut = new StringBuilder((int)pcchOut);
   AssocQueryString(AssocF.Verify, assocStr, doctype, null, pszOut, ref pcchOut);
   return pszOut.ToString();
}