using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        IDictionary<int, string> dict = null;

        Console.WriteLine($"-------------------- DICTIONARY NULL --------------------");

        Console.WriteLine($"dict.AnyNotNull(): {dict.AnyNotNull()}");

        Console.WriteLine($"dict.ContainsKeyNotNull(1): {dict.ContainsKeyNotNull(1)}");

        Console.WriteLine($"dict.ContainsKeyNotNull(5): {dict.ContainsKeyNotNull(5)}");

        string uno = null;

        Console.WriteLine($"dict.TryGetValueNotNull(1, out uno): {dict.TryGetValueNotNull(1, out uno)}");

        Console.WriteLine($"uno: {uno}");

        string cinco = null;

        Console.WriteLine($"dict.TryGetValueNotNull(5, out cinco): {dict.TryGetValueNotNull(5, out cinco)}");

        Console.WriteLine($"cinco: {cinco}");

        Console.WriteLine($"dict.ToListString(): {dict.ToListString<int,string>()}");

        Console.WriteLine();

        dict = new Dictionary<int,string>()

        {

            {1, "uno"},

            {2, "dos"},

            {3, "tres"},

        };

        Console.WriteLine($"-------------------- DICTIONARY NOT NULL --------------------");

        Console.WriteLine($"dict.AnyNotNull(): {dict.AnyNotNull()}");

        Console.WriteLine($"dict.ContainsKeyNotNull(1): {dict.ContainsKeyNotNull(1)}");

        Console.WriteLine($"dict.ContainsKeyNotNull(5): {dict.ContainsKeyNotNull(5)}");

        Console.WriteLine($"dict.TryGetValueNotNull(1, out uno): {dict.TryGetValueNotNull(1, out uno)}");

        Console.WriteLine($"uno: {uno}");

        Console.WriteLine($"dict.TryGetValueNotNull(5, out cinco): {dict.TryGetValueNotNull(5, out cinco)}");

        Console.WriteLine($"cinco: {cinco}");

        Console.WriteLine($"dict.ToListString(): {dict.ToListString<int,string>()}");

    }

}

​

public static class DictionaryExtension

{

    public static string ToListString<K,V>(this IDictionary<K,V> dict, string itemSeparator = "|" , string keyValueSeparator = "-")

    {

        return dict.AnyNotNull() ? string.Join($"{itemSeparator}" , dict.Select(d => $"{d.Key}{keyValueSeparator}{d.Value}")) : null;

    }

    public static bool AnyNotNull<K,V>(this IDictionary<K,V> dict)

    {

        return dict != null && dict.Count > 0;

    }

    public static bool ContainsKeyNotNull<K,V>(this IDictionary<K,V> dict, K key)

    {

        return dict != null && dict.ContainsKey(key) ;

    }

    public static bool TryGetValueNotNull<K,V>(this IDictionary<K,V> dict, K key, out V val)

    {

        V outVal = default(V);

        bool isSuccess = dict != null && dict.TryGetValue(key, out outVal) ;

        val = outVal;

        return isSuccess;

    }

    public static IList<T> Split<T>(string str, string separator)

    {

        if(string.IsNullOrEmpty(str)) 

            return new List<T>();

​

        return str.Split(separator).Select(i => (T)Convert.ChangeType(i, typeof(T))).ToList();

    }

}

​