Quick tips

Create Unique Ids

GUID is 128 bit (16 bytes) data. To convert GUID to integer without data loss, we cannot use Int32 or Int64.

.NET 4.0 introduced BigInteger struct which is 128 bit integer. And GUID can be easily converted to BigInteger as follows.

using System;
using System.Numerics;

class Program
{
    static void Main(string[] args)
    {
        // ex: 8a847645-8cac-422c-962a-fdf3aa220065
        Guid g = Guid.NewGuid();

        // Convert GUID to BigInteger
        // ex: 134252730720501571475137903438348973637
        BigInteger bigInt = new BigInteger(g.ToByteArray());
    }
}

Guid = Guid.NewGuid()

var id64Generator = new Id64Generator();

public string generateID(string sourceUrl)
{
    return string.Format("{0}_{1}", sourceUrl, id64Generator.GenerateId());
}

// node 0
var id64Generator = new Id64Generator(0);

// node 1
var id64Generator = new Id64Generator(1);

// ... node 10
var id64Generator = new Id64Generator(10);

internal static class CorrelationIdGenerator
{
    // Base32 encoding - in ascii sort order for easy text based sorting
    private static readonly char[] s_encode32Chars = "0123456789ABCDEFGHIJKLMNOPQRSTUV".ToCharArray();

    // Seed the _lastConnectionId for this application instance with
    // the number of 100-nanosecond intervals that have elapsed since 12:00:00 midnight, January 1, 0001
    // for a roughly increasing _lastId over restarts
    private static long _lastId = DateTime.UtcNow.Ticks;

    public static string GetNextId() => GenerateId(Interlocked.Increment(ref _lastId));

    private static string GenerateId(long id)
    {
        return string.Create(13, id, (buffer, value) =>
        {
            char[] encode32Chars = s_encode32Chars;

            buffer[12] = encode32Chars[value & 31];
            buffer[11] = encode32Chars[(value >> 5) & 31];
            buffer[10] = encode32Chars[(value >> 10) & 31];
            buffer[9] = encode32Chars[(value >> 15) & 31];
            buffer[8] = encode32Chars[(value >> 20) & 31];
            buffer[7] = encode32Chars[(value >> 25) & 31];
            buffer[6] = encode32Chars[(value >> 30) & 31];
            buffer[5] = encode32Chars[(value >> 35) & 31];
            buffer[4] = encode32Chars[(value >> 40) & 31];
            buffer[3] = encode32Chars[(value >> 45) & 31];
            buffer[2] = encode32Chars[(value >> 50) & 31];
            buffer[1] = encode32Chars[(value >> 55) & 31];
            buffer[0] = encode32Chars[(value >> 60) & 31];
        });
    }
}

Looping

foreach with index

foreach ((string msg, int index) in messageStringList.Select((msg, index) => (msg, index)))
	{
		if (!msg.Contains("https:")) continue;
		interactionResponse.output.content.Add(await BuildResponseWithLinks(msg, index, messageStringList));
	}

Dictionary

get properties and values of object

Dictionary<string, object> customParams = visitor
                                             .GetType()
                                             .GetProperties(BindingFlags.Instance | BindingFlags.Public)
                                             .ToDictionary(keySelector: prop => prop.Name, elementSelector: prop => prop.GetValue(visitor, index: null));

String

split

string[] separatingStrings = { "https://" };
string[] words = msg.Split(separatingStrings, System.StringSplitOptions.RemoveEmptyEntries);

Regex

Regex urlPattern = new Regex(@"(?:(?<=\\n|\n|\s\w*)https:\/\/.*?(?<=\s|$))", RegexOptions.Compiled | RegexOptions.IgnorePatternWhitespace | RegexOptions.IgnoreCase);
						MatchCollection matches = urlPattern.Matches(message);

						foreach (Match match in matches) { Console.WriteLine(message.Substring(match.Index, match.Length)); }

string mystring = "Here are some linked FAQs that might answer that:  \nhttps://dev.veridiancu.org/faq/8107/what-is-an-hsa-health-savings-account and here this \nhttps://dev.veridiancu.org/faq/8108/how-do-i-qualify-for-a-health-savings-account  and here this \nhttps://dev.veridiancu.org/faq/8106/can-i-open-a-cd-on-my-hsa";

System.Text.RegularExpressions.Regex urlPattern = new System.Text.RegularExpressions.Regex(@"(?:(?:\\n|\n|\s\w*)https:\/\/.*?(?:\s|$))", System.Text.RegularExpressions.RegexOptions.Compiled | System.Text.RegularExpressions.RegexOptions.IgnorePatternWhitespace | System.Text.RegularExpressions.RegexOptions.IgnoreCase);

 System.Text.RegularExpressions.MatchCollection matches = urlPattern.Matches( msg);

string[] stringArray = urlPattern.Split(msg);

 string result = urlPattern.Replace(mystring, delegate(System.Text.RegularExpressions.Match m) {
                               System.Text.RegularExpressions.Match urlMatch = System.Text.RegularExpressions.Regex.Match(m.Value, @"
                                                                                                          (https:\/\/)(.*?)(\s|$)");
                                                                return $"~{urlMatch.Value}~";
                                                             });

   var nn = result.Split('~');

Stream

using System;
using System.Threading.Tasks;
using System.Windows;
using System.IO;

namespace WpfApplication
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private async void Button_Click(object sender, RoutedEventArgs e)
        {
            string StartDirectory = @"c:\Users\exampleuser\start";
            string EndDirectory = @"c:\Users\exampleuser\end";

            foreach (string filename in Directory.EnumerateFiles(StartDirectory))
            {
                using (FileStream SourceStream = File.Open(filename, FileMode.Open))
                {
                    using (FileStream DestinationStream = File.Create(EndDirectory + filename.Substring(filename.LastIndexOf('\\'))))
                    {
                        await SourceStream.CopyToAsync(DestinationStream);
                    }
                }
            }
        }
    }
}

Text Writer

using System.IO;

namespace ConsoleApplication
{
    class Program4
    {
        static void Main()
        {
            WriteCharacters();
        }

        static async void WriteCharacters()
        {
            using (StreamWriter writer = File.CreateText("newfile.txt"))
            {
                await writer.WriteLineAsync("First line of example");
                await writer.WriteLineAsync("and second line");
            }
        }
    }
}

File & Directory

string currentDir = Directory.GetCurrentDirectory();
string path = Path.Combine(new FileInfo(Assembly.GetExecutingAssembly().Location).DirectoryName,"vcu-chat-bot");
FileStream stream = new(path, FileMode.Open, FileAccess.Read);