Public MustOverride Function IsUserInRole ( _
    username As String, _
    roleName As String _
) As Boolean

Dim instance As RoleProvider
Dim username As String
Dim roleName As String
Dim returnValue As Boolean

returnValue = instance.IsUserInRole(username, roleName)

public abstract bool IsUserInRole (
    string username,
    string roleName
)

public:
virtual bool IsUserInRole (
    String^ username, 
    String^ roleName
) abstract

public abstract boolean IsUserInRole (
    String username, 
    String roleName
)

public abstract function IsUserInRole (
    username : String, 
    roleName : String
) : boolean

Public Overrides Function IsUserInRole(username As String, rolename As String) As Boolean 
  If username Is Nothing OrElse username = "" Then _
    Throw New ProviderException("User name cannot be empty or null.")
  If rolename Is Nothing OrElse rolename = "" Then _
    Throw New ProviderException("Role name cannot be empty or null.")

  Dim userIsInRole As Boolean = False

  Dim conn As OdbcConnection = New OdbcConnection(connectionString)
  Dim cmd As OdbcCommand = New OdbcCommand("SELECT COUNT(*) FROM [" & usersInRolesTable & "]" & _
                                           " WHERE Username = ? AND Rolename = ? AND ApplicationName = ?", conn)

  cmd.Parameters.Add("@Username", OdbcType.VarChar, 255).Value = username
  cmd.Parameters.Add("@Rolename", OdbcType.VarChar, 255).Value = rolename
  cmd.Parameters.Add("@ApplicationName", OdbcType.VarChar, 255).Value = ApplicationName

  Try
    conn.Open()

    Dim numRecs As Integer = CType(cmd.ExecuteScalar(), Integer)

    If numRecs > 0 Then
      userIsInRole = True
    End If
  Catch e As OdbcException
    ' Handle exception.
  Finally
    conn.Close()      
  End Try

  Return userIsInRole
End Function

public override bool IsUserInRole(string username, string rolename)
{
  if (username == null || username == "")
    throw new ProviderException("User name cannot be empty or null.");
  if (rolename == null || rolename == "")
    throw new ProviderException("Role name cannot be empty or null.");

  bool userIsInRole = false;

  OdbcConnection conn = new OdbcConnection(connectionString);
  OdbcCommand cmd = new OdbcCommand("SELECT COUNT(*) FROM [" + usersInRolesTable + "]"  +
                                    " WHERE Username = ? AND Rolename = ? AND ApplicationName = ?", conn);

  cmd.Parameters.Add("@Username", OdbcType.VarChar, 255).Value = username;
  cmd.Parameters.Add("@Rolename", OdbcType.VarChar, 255).Value = rolename;
  cmd.Parameters.Add("@ApplicationName", OdbcType.VarChar, 255).Value = ApplicationName;

  try
  {
    conn.Open();

    int numRecs = (int)cmd.ExecuteScalar();

    if (numRecs > 0)
    {
      userIsInRole = true;
    }
  }
  catch (OdbcException)
  {
    // Handle exception.
  }
  finally
  {
    conn.Close();      
  }

  return userIsInRole;
}