Proper way to initialize a C# dictionary with values

Question

I am creating a dictionary in a C# file with the following code:

private readonly Dictionary<string, XlFileFormat> FILE_TYPE_DICT         = new Dictionary<string, XlFileFormat>         {             {"csv", XlFileFormat.xlCSV},             {"html", XlFileFormat.xlHtml}         }; 

There is a red line under new with the error:

Feature 'collection initilializer' cannot be used because it is not part of the ISO-2 C# language specification

What is going on here?

I am using .NET version 2.

Answer 1

I can't reproduce this issue in a simple .NET 4.0 console application:

static class Program {     static void Main(string[] args)     {         var myDict = new Dictionary<string, string>         {             { "key1", "value1" },             { "key2", "value2" }         };          Console.ReadKey();     } } 

Can you try to reproduce it in a simple Console application and go from there? It seems likely that you're targeting .NET 2.0 (which doesn't support it) or client profile framework, rather than a version of .NET that supports initialization syntax.

Answer 2

With C# 6.0, you can create a dictionary in the following way:

var dict = new Dictionary<string, int> {     ["one"] = 1,     ["two"] = 2,     ["three"] = 3 }; 

It even works with custom types.