Null value of DataReader in List(of string) vb.net - arrays

Question

I am writing a web service function in VB.net in a stored procedure in SQL server. I think the DataReader does not return any value.
Here is my stored procedure in Sql Server:
Create proc getVillageName
#village varchar(50)
as
Begin
SELECT
lookup_table.value FROM dbo.lookup_table INNER JOIN dbo.lookup_description ON
lookup_table.group_id = lookup_description.desc_id WHERE
lookup_description.description = 'Village' AND
lookup_table.value LIKE #village + '%'
End
Here is my code:
Public Function GetVillage(ByVal villageName As String) As List(Of String)
Dim strsql As String
Dim Villagevalue As List(Of String)
Dim param As SqlParameter
Dim conn As New SqlConnection With {.ConnectionString = "Server=MINTOY_DEV\MIGSSERVER;Database=SouthLinkDBO;User=sa;Pwd=123;"}
Dim cmd As New SqlCommand
Dim reader As SqlDataReader
Using conn
strsql = "getVillageName"
cmd = New SqlCommand(strsql, conn)
cmd.CommandType = CommandType.StoredProcedure
param = New SqlParameter("#village", villageName)
cmd.Parameters.Add(param)
conn.Open()
reader = cmd.ExecuteReader
While reader.Read
Villagevalue.Add(reader.Item("value").ToString)
End While
End Using
End Function

Answer 1

You're missing a line:
While reader.Read
Villagevalue.Add(reader.Item("value").ToString)
End While
End Using
Return Villagevalue '<-----------------
End Function
Are you looking at compiler warnings? VB will tell you if you forget a Return statement.
Better yet, open the Project Properties, click on the Compiler tab, and set "Function returning a reference type without a return value" to "Error".
Also, how is this working at all?
Dim Villagevalue As List(Of String)
That should be
Dim Villagevalue As New List(Of String)

Answer 2

Lots of things we can improve here:
Public Iterator Function GetVillage(ByVal villageName As String) As IEnumerable(Of String)
Using conn As New SqlConnection("Server=MINTOY_DEV\MIGSSERVER;Database=SouthLinkDBO;User=sa;Pwd=123;"), _
cmd As New SqlCommand("getVillageName", conn)
cmd.CommandType = CommandType.StoredProcedure
cmd.Parameters.Add("#village", SqlDbType.VarChar, 50).Value = villageName
conn.Open()
Using rdr As SqlDataReader = cmd.ExecuteReader()
While reader.Read()
Yield DirectCast(reader("value"), String)
End While
End Using
End Using
End Function
The big thing is we actually return a value (Yield handles this for Iterator functions).
If you really need an actual List(Of String) (Hint: you usually don't; Your code will almost always perform a lot better if you arrange things to work with IEnumerable(Of T) for as long as possible) you can append a .ToList() when calling this method.