using System.Collections.Generic;
public static void Main()
Dictionary<string, object> ItemSource;
ItemSource = new Dictionary<string, object>();
ItemSource.Add("test1", "رحیمی");
ItemSource.Add("test2", "سالاری");
var source = ItemSource.Where(a => a.Value.ToString().Contains("ر"));
foreach(KeyValuePair<string, object> pair in source)
Console.WriteLine(pair.Value);