Not able to match string with list of string

Question

I have one string which getting the value from user inserted value and i have a list of name which is in a list of string type which comes from the database.

now the condition

 

1= i need to check if the user input value is matched with any value from the list of string and it should be the exact match not part of a name

 

2=if my databse row contain like " fullstack .net devloper" and my user value is either "fullstack" or ".net" or "devloper" .how can i check this thing.

like if i check for ".net " it will not be exact match with " fullstack .net devloper",but all this "fullstack" and ".net" and "devloper" are there is the database.

how can i do this thing?this is in VB.net.anyone can do in c# also .please need help

 

Public Shared Function CheckLastNameInSuspectLastNameLUCache(ByVal sLastname As String) As Boolean

Dim matchKeywordLUCache As FakeLastNameLUCache = TheMatrix.LookupCacheList.GetLUCache(Of FakeLastNameLUCache)()

Dim matchKeywordList As List(Of String) = (matchKeywordLUCache.LookupData.Keys).Cast(Of String)().ToList()