Obsolete attribute - Avoid magic string

Question

I want to mark an old class as Obsolete and redirect to the new class in the Obsolete attribute comment. However, if I write the new class name as a magic string, I won't be able to use the might of IDE.

For example, if I rename my class, I will loose the "link". And the reader won't be able to Ctrl + click on my comment to go to the new class.

The official documentation does seems to say that it is not possible, but I find strange that nobody has this need.

Instead of

// Mark OldProperty As Obsolete.
[ObsoleteAttribute("This property is obsolete. Use NewProperty instead.", false)]
public static string OldProperty
{ get { return "The old property value."; } }

public static string NewProperty
{ get { return "The new property value."; } }

I would like to be able to write

[ObsoleteAttribute($"This property is obsolete. Use {nameof(NewProperty)} instead.", false)]

As a workaround, I can use the XML doc, but it's not the best way to do it.

/// <remarks>Replaced by <see cref="LoadBrainIndMeasMessTable"/></remarks>

Answer 1

This is already supported in C# 10 (.NET 6):

public class C
{
    [Obsolete($"This property is obsolete. Use {nameof(NewProperty)} instead")]
    public static string OldProperty => "The old property value.";

    public static string NewProperty => "The new property value.";
}

Before then, string concatenation should work for any C# version:

public class C
{
    [Obsolete("This property is obsolete. Use " + nameof(NewProperty) + " instead")]
    public static string OldProperty => "The old property value.";

    public static string NewProperty => "The new property value.";
}