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fredyfx
Asked: 2020-09-25 13:57:48 +0800 CST 2020-09-25 13:57:48 +0800 CST

How to define a Static Dictionary with initialized elements in C#?

  • 772

Good morning SOes brothers, I have this situation:

I need a dictionary with data previously defined, this dictionary is supposed to be read-only so the million dollar question is:

How can I define a static dictionary with initialized elements?

This way when you have to work some clave, the valorwill be obtained from the dictionary.

c#

2 Answers

  1. Best Answer

    If the data in that dictionary is read-only and it's a dictionary for the whole class, do it staticand of typereadonly 

    public class ClaseDeEjemplo {

    public static readonly Dictionary<string, string> ejemploDiccionario = new Dictionary<string, string>() {           
        {"Clave1", "Valor1"},
        {"Clave2", "Valor2"},
        {"Clave3", "Valor3"}
    };

}

    And you use it as follows:

    var ValorDependiendoDeLaClave = ejemploDiccionario[VariableDeNombreDeAlgunaClave];

    That is, if in VariableDeNombreDeAlgunaClavecontains a string named Clave1, the value will be Valor1.

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  2. Instead of a Dictionary you use a ReadOnlyDictionary:

    readonly static IReadOnlyDictionary<string, int> dictionary;

static TheClass() // TheClass es el nombre de la clase que contendrá el diccionario estático
{
    var dict = new Dictionary<string, int>{
        ["1"] = 1,
        ["2"] = 2,
        ["3"] = 3
    };

    dictionary = new ReadOnlyDictionary<stringm, int>(dict);
}

    Or if you use a version of Visual Studio lower than 2015:

    readonly static IReadOnlyDictionary<string, int> dictionary;

static TheClass() // TheClass es el nombre de la clase que contendrá el diccionario estático
{
    var dict = new Dictionary<string, int>{
        { "1", 1 },
        { "2", 2 },
        { "3", 3 }
    };

    dictionary = new ReadOnlyDictionary<stringm, int>(dict);
}

    Although I prefer the first option, it is clearer that they are data from a dictionary.

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