Hasan A Yousef Hasan A Yousef - 1 year ago 86
C# Question

Invoke Action by reference

I'm new to C#, and it looks I need to use

Dictionary<string, Action>

So I wrote the below code:

using System;
using System.Collections.Generic;

public class Program
public static void Main()
var functions = new Dictionary<string, Action<string[]>>();
functions.Add("Foo", CountParameters);
functions.Add("Bar", SomeOtherMethodName);

Console.WriteLine("Hello World");

Action<string[]> action;
if (functions.TryGetValue("Foo", out action))
// What shall I write here to invoke the action!?
// No function with that name

public static void CountParameters(string[] args)
Console.WriteLine("Fn 1");

public static void SomeOtherMethodName(string[] args)
Console.WriteLine("Fn 2");

My Question is of 2 parts:

  1. How shall I invoke the
    if the condition is true.

  2. I understood the
    is a
    return, but it looks an input
    is a must, in my case, i do not have an
    input args
    nor an
    so is
    what I need, or could be something else?

Answer Source

If all your methods don't don't have return values, an Action<string[]> is fine. If they even don't require parameters, you could simply use the non-generic Action-delegate and leave out the string[]-parameter.

var functions = new Dictionary<string, Action>();
functions.Add("Foo", CountParameters);

Regarding the invocation: The way you've done it in your code snippet is fine if you leave out the (unnecessary) string[]-parameter. Just invoke the Action-delegate taken from the dictionary like you already did without any parameters: action();

Instead of attaching the brackets () you could alternatively call action.Invoke();.

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