this is actual problem
Public Function GetData(ByVal sSQL As String)
Dim cnCustomers As OleDbConnection
Dim sqlCmd As OleDbCommand = New OleDbCommand(sSQL)
Dim myData As OleDbDataReader
cnCustomers = New OleDbConnection(cnString)
Try
cnCustomers.Open()
sqlCmd.Connection = cnCustomers
myData = sqlCmd.ExecuteReader
Return myData
Catch ex As Exception
Return ex
End Try
End Function
see underlined portion compare them
when exception occur it return ex which is object of
Exception class
and in normal case it returns
OleDbDataReader mydata
and your
FillListView is taking second argument as
OleDbDataReader
so change that return statement,
Catch ex As Exception
Return Nothing
End Try
Happy Coding!
:)