using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string test = "postedByUser='Jason, Bourne' postedById='48775' Text='Some text in here' postedDate='2020-04-21'";

        var dict = test.Split(new string[] { "' "}, StringSplitOptions.None).Select(t=>string.Concat(t,"'").Split(new string[] { "="}, StringSplitOptions.None)).ToDictionary(t=>t[0],t=>t[1]);

        foreach(var d in dict){

           Console.WriteLine(d.Key+" "+d.Value);    

        }

    }

}