XML documentation of Action parameters in C#

Question

I am looking for a way to document action parameters in C#. Code looks like this:

/// <summary>
/// Do some action with parameters.
/// </summary>
/// <params name="someAction"> This is action but what about parameters? </param>
public void Do(Action<int,int,string> someAction)

How can I name and document parameters of "someAction" so that they would appear in intellisense?

Answer 1

You can use a nested structure.

/// <summary>
/// Does something useful.
/// </summary>
/// <param name="c">A constant</param>
/// <param name="someAction">
///     Here is an action.
///     <param name="someAction arg1">Count</param>
///     <param name="someAction arg2">Length</param>
///     <param name="someAction arg2">Content</param>
/// </param>
public void Do(int c, Action<int,int,string> someAction){}

It looks like this in the editor:

However, for complex structures, this is harder to maintain in the long run. If the context is not apparent intuitively, it is better and safer to create a class.

public class MyActionArgs : ActionArgs
{
    public MyActionArgs(int count, int length, string content)
    {
        Count = count;
        Length = length;
        Content = content ?? throw new ArgumentNullException(nameof(content));
    }

    public int Count { get; }
    public int Length { get; }
    public string Content { get; }
}

public void Do(Action<MyActionArgs> myAction){} 

Answer 2

In short - not possible. Few possible workarounds:

• Use a class or a structure instead of multiple parameters. Eg. instead of Action<int,int,int> use Action<ThreePigletsClass>
• Minimize the number of parameters if possible. Maybe some are not necessary and simple Action would work.
• Write parameter comments... which does not help much but gets you Stackoverflow points.
• If not alergic to delegates use them instead.