C# debugging: [DebuggerDisplay] or ToString()?

Question

Hey all,

There are two ways I know of to increase the usefulness of debugging information so you don't see {MyNamespace.MyProject.MyClass} in the debugger. These are the use of the DebuggerDisplay attribute and the ToString method.

[DebuggerDisplay("Name = {Name}")]
public class Person
{
    public string Name;
}

or

public class Person
{
    public string Name;
    public override string ToString()
    {
        return string.Format("Name = {0}", Name);
    }
}

Is there any reason to prefer one to the other? Any reason not to do both? Is it purely personal preference?

Answer 1

Using [DebuggerDisplay] is meant only for the debugger. Overriding ToString() has the "side effect" of changing the display at runtime.

This may or may not be a good thing.

Often, you want more info during debugging than your standard ToString() output, in which case you'd use both.

For example, in your case, the "ToString" implementation seems odd to me. I would expect a "Person" class ToString() implementation to just return the Name directly, not "Name = PersonsName". However, during debugging, I might want that extra information.