Obligation to call a method

Question

In VB .NET, when you create a user control class, you have the obligation to call the sub InitializeComponent within the constructor.

If you don't you'll a warning message like this :

'Public Sub New()' in designer-generated type 'MyUserControl' should call InitializeComponent method.

What is the mechanism used to raise this warning? Is it something I can reproduce for my own functions?

Hans Passant Hans Passant · Accepted Answer · 2011-01-27T14:58:32

This is built-in behavior for the VB.NET compiler. This sample class triggers it:

<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Public Class Class1
    Public Sub New()
       '' Warning BC40054 generated here
    End Sub
End Class

The attribute matters. It is not otherwise generically useful behavior, you cannot tell the compiler to make it generate a similar warning using your own attribute.

Obligation to call a method

1 Answers