Question

Is there an annotation in .NET which allows methods or classes to be deprecated so that their use and their callers are identified by the compiler (cf @Deprecated in Java)

Answer 1

The [Obsolete] attribute.

You can add a comment on what people should be using, for example:

[Obsolete("Use NewMethod() instead")]
public void OldMethod()
{
}

If you want to generate a compiler error when people use your method:

[Obsolete("Use NewMethod() instead", true)]
public void OldMethod()
{
}

This is an example for a method, but it can be used on almost any attribute target. See here for full docs.

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Since the question was edited slightly, I’ll add the VB.NET syntax as well, to cover the most common .NET languages:

<Obsolete("Use NewMethod() instead")> _
Public Sub OldMethod()
End Sub