<DllImportAttribute("VISA32.DLL", EntryPoint:="#141", ExactSpelling:=True, CharSet:=CharSet.Ansi, SetLastError:=True, CallingConvention:=CallingConvention.Winapi)> _
Public Shared Function viOpenDefaultRM(ByRef sesnû As Integer) As Integer
End Function

Public Declare Function viOpenDefaultRM2 Lib "VISA32.DLL" Alias "#141" (ByRef sesn As Integer) As Integer

Example 1: Declaring unmanaged functions in VB.NET. (a) Using .NET attributes; (b) using VB-style declare.