using System;

using System.Linq;

using System.Collections.Generic;

using System.Data;

​

public class Program

{

    public static void Main()

    {

        #region Mock DataTable

        DataTable dt = new DataTable();

        dt.Columns.Add("Key", typeof(string));

        dt.Columns.Add("Value", typeof(string));

        var rowOne = dt.NewRow();

        rowOne["Key"] = "userName";

        rowOne["Value"] = "userNameValue";

        var rowTwo = dt.NewRow();

        rowTwo["Key"] = "password";

        rowTwo["Value"] = "passwordValue";

        var rowThree = dt.NewRow();

        rowThree["Key"] = "domain";

        rowThree["Value"] = "domainValue";

        dt.Rows.Add(rowOne);

        dt.Rows.Add(rowTwo);

        dt.Rows.Add(rowThree);

        #endregion

        Dictionary<string, string> dict = new Dictionary<string, string>();

        foreach(DataRow row in dt.Rows)

        {

            dict.Add(row["Key"].ToString(), row["Value"].ToString());

        }

        foreach (var kvp in dict)

        {

            Console.WriteLine($"Key: {kvp.Key}, Value: {kvp.Value}");

        }

    }

}