Is it possible to initialise a New System.Collections.Generic.Dictionary with String key/value pairs?

Is it possible to create and initialise a System.Collections.Generic.Dictionary object with String key/value pairs in one statement?

I'm thinking along the lines of the constructor for an array of Strings..

e.g.

Private mStringArray As String() = {"String1", "String2", "etc"}

In case this is turns out to be a syntactic sugar kind of thing, I'd prefer an answer that I can use in .Net 2.0 (Visual Studio 2005), and Visual Basic - though I'm curious if it's possible at all so don't let that put you off ;o)

Answers


I don't think there is a way to do this out of the box in VB.NET 2, however you can extend the generic dictionary to make it work the way you want it to.

The console app below illustrates this:

Imports System.Collections.Generic

Module Module1

    Sub Main()

        Dim items As New FancyDictionary(Of Integer, String)(New Object(,) {{1, "First Item"}, {2, "Second Item"}, {3, "Last Item"}})
        Dim enumerator As FancyDictionary(Of Integer, String).Enumerator = items.GetEnumerator

        While enumerator.MoveNext
            Console.WriteLine(String.Format("{0} : {1}", enumerator.Current.Key, enumerator.Current.Value))
        End While

        Console.Read()

    End Sub

    Public Class FancyDictionary(Of TKey, TValue)
        Inherits Dictionary(Of TKey, TValue)

        Public Sub New(ByVal InitialValues(,) As Object)

            For i As Integer = 0 To InitialValues.GetLength(0) - 1

                Me.Add(InitialValues(i, 0), InitialValues(i, 1))

            Next

        End Sub

    End Class

End Module

Like this:

Dim myDic As New Dictionary(Of String, String) From {{"1", "One"}, {"2", "Two"}}

Try this syntax:

Dictionary<string, double> dict = new Dictionary<string, double>()
{
  { "pi", 3.14},
  { "e", 2.71 }
 };

But that may require C# 3 (.NET 3.5)


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