Convert object to KeyValuePair

Question

I have an IEnumerable<Entityclass> for an entity that has a string and an int member. i need to convert it to an array of KeyValuePair<string, double> and vice versa.

It fails with a cast error.

[DataContract]
public class Entityclass
{
    [DataMember]
    public string text{ get; set; }
    [DataMember]
    public int textcount{ get; set; }
 }

I have IEnumerable<Entityclass>

• How do I convert from IEnumerable<Entityclass> to an array of KeyvaluePair<string, double>[]?

• How do I convert the KeyvaluePair<string, double>[] array to a KeyvaluePair<string, int>[] array ?

• How do I convert KeyvaluePair<string, double> back to an IEnumerable?

I have tried:

• topics is IEnumerable<Entityclass>;
• topics.Cast<KeyValuePair<string, double>>().ToArray(); Fails with cast error

Answer 1

You need to project each topic into a KeyValuePair. The Linq Select extension method does that:

topics
    .Select(x=> new KeyValuePair<string, double>(x.text, x.textcount))
    .ToArray();