public class Article1
{
    public string Title { get; set; }
    public string? Subtitle { get; set; }
    public string Author { get; set; }
    public DateTime Published { get; set; }
}

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net7.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
</Project>

Non-nullable property 'Title' must contain a non-null value when exiting constructor. Consider declaring the property as nullable. [CS11Tests]csharp(CS8618)
Non-nullable property 'Author' must contain a non-null value when exiting constructor. Consider declaring the property as nullable. [CS11Tests]csharp(CS8618)

public class Article2
{
    public Article2(string title, string subtitle, string author, DateTime published)
    {
        Title = title;
        Subtitle = subtitle;
        Author = author;
        Published = published;
    }

    public Article2(string title, string author, DateTime published)
    {
        Title = title;
        Author = author;
        Published = published;
    }

    public string Title { get; set; }
    public string? Subtitle { get; set; }
    public string Author { get; set; }
    public DateTime Published { get; set; }
}

 Article2 article = new("C# 11 Required Keyword", "A new language feature", "Name",  new DateTime(2022, 11, 12));

 public string Title { get; set; } = default!;

public class Article3
{
    public required string Title { get; set; }
    public string? Subtitle { get; set; }
    public required string Author { get; set; }
    public DateTime Published { get; set; }
}

public class Book
{
    public Book() => Name = string.Empty;

    public Book(string name) => Name = name;

    public required string Name { get; set; }
}

Book book = new("Book's Name");

Required member 'Book.Name' must be set in the object initializer or attribute constructor. [CS11Tests]csharp(CS9035)

public class Book
{
    [SetsRequiredMembers]
    public Book() => Name = string.Empty;

    [SetsRequiredMembers]
    public Book(string name) => Name = name;

    public required string Name { get; set; }
}

در اینجا مقدار Hex برایمان قابل فهم نیست. سناریویی را در نظر بگیرید که مقادیر باید داخل دیتابیس به صورت Hex نگهداری شوند، اما می‌خواهیم هنگام دیباگ، مقدار پراپرتی HexValue به صورت قابل درک و decimal آن نمایش داده شود.

برای انجام اینکار میتوانیم از DebuggerTypeProxy استفاده کنیم. ابتدا کلاسی ایجاد میکنیم که بعنوان proxy، مقادیر را به شکلی که نیاز داریم نمایش دهد. این کلاس object اصلی را در Constructor دریافت کرده و مقادیر مورد نظرمان، از طریق property هایی که در آن تعریف می‌کنیم قابل دسترسی هستند:

public class DataDebugView
{
    private readonly Data _data;

    public DataDebugView(Data data)
    {
        _data = data;
    }

    public string DecimalValue
    {
        get
        {
            bool isValidHex = int.TryParse(_data.HexValue, System.Globalization.NumberStyles.HexNumber, null, out var value);
            return isValidHex ? value.ToString() : "INVALID HEX STRING";
        }
    }
}

در نهایت برای اعمال کردن این کلاس proxy، از ویژگی DebuggerTypeProxy بر روی کلاس اصلی استفاده می‌کنیم:

[DebuggerTypeProxy(typeof(DataDebugView))]
public class Data
{
    public string Name { get; set; }

    public string HexValue { get; set; }
}

بعد از اعمال تغییرات و اجرای دوباره برنامه، نحوه نمایش مقادیر کلاس به این صورت تغییر خواهند یافت:

  <connectionStrings>
    <clear />
    <add name="Sample07Context" connectionString="Data Source=(local);Initial Catalog=TestDbIoC;Integrated Security = true" providerName="System.Data.SqlClient" />
    <add name="Database2012" connectionString="Data Source=(local);Initial Catalog=testdb2012;Integrated Security = true" providerName="System.Data.SqlClient" />
  </connectionStrings>

using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using EF_Sample07.DomainClasses;
 
namespace EF_Sample07.DataLayer.Context
{
    public class Sample07Context : DbContext, IUnitOfWork
    {
        public DbSet<Category> Categories { set; get; }
        public DbSet<Product> Products { set; get; }
 
        /// <summary>
        /// It looks for a connection string named Sample07Context in the web.config file.
        /// </summary>
        public Sample07Context()
            : base("Sample07Context")
        {
        }
 
        /// <summary>
        /// To change the connection string at runtime. See the SmObjectFactory class for more info.
        /// </summary>
        public Sample07Context(string connectionString)
            : base(connectionString)
        {
            //Note: defaultConnectionFactory in the web.config file should be set.
        }
 
 
        public void SetConnectionString(string connectionString)
        {
            this.Database.Connection.ConnectionString = connectionString;
        }
    }
}

using System;
using System.Threading;
using System.Web;
using EF_Sample07.DataLayer.Context;
using EF_Sample07.ServiceLayer;
using StructureMap;
using StructureMap.Web;
using StructureMap.Web.Pipeline;
 
namespace EF_Sample07.IoCConfig
{
    public static class SmObjectFactory
    {
        private static readonly Lazy<Container> _containerBuilder =
            new Lazy<Container>(defaultContainer, LazyThreadSafetyMode.ExecutionAndPublication);
 
        public static IContainer Container
        {
            get { return _containerBuilder.Value; }
        }
 
        public static void HttpContextDisposeAndClearAll()
        {
            HttpContextLifecycle.DisposeAndClearAll();
        }
 
        private static Container defaultContainer()
        {
            return new Container(ioc =>
            {
                // session manager setup
                ioc.For<ISessionProvider>().Use<DefaultWebSessionProvider>();
                ioc.For<HttpSessionStateBase>()
                   .Use(ctx => new HttpSessionStateWrapper(HttpContext.Current.Session));
 
                ioc.For<IUnitOfWork>()
                   .HybridHttpOrThreadLocalScoped()
                   .Use<Sample07Context>()
                    // Remove these 2 lines if you want to use a connection string named Sample07Context, defined in the web.config file.
                   .Ctor<string>("connectionString")
                   .Is(ctx => getCurrentConnectionString(ctx));
 
                ioc.For<ICategoryService>().Use<EfCategoryService>();
                ioc.For<IProductService>().Use<EfProductService>();
 
                ioc.For<ICategoryService>().Use<EfCategoryService>();
                ioc.For<IProductService>().Use<EfProductService>();
 
                ioc.Policies.SetAllProperties(properties =>
                {
                    properties.OfType<IUnitOfWork>();
                    properties.OfType<ICategoryService>();
                    properties.OfType<IProductService>();
                    properties.OfType<ISessionProvider>();
                });
            });
        }
 
        private static string getCurrentConnectionString(IContext ctx)
        {
            if (HttpContext.Current != null)
            {
                // this is a web application
                var sessionProvider = ctx.GetInstance<ISessionProvider>();
                var connectionString = sessionProvider.Get<string>("CurrentConnectionString");
                if (string.IsNullOrWhiteSpace(connectionString))
                {
                    // It's a default connectionString.
                    connectionString = "Database2012";
                    // this session value should be set during the login phase
                    sessionProvider.Store("CurrentConnectionStringName", connectionString);
                }
 
                return connectionString;
            }
            else
            {
                // this is a desktop application, so you can store this value in a global static variable.
                return "Database2012";
            }
        }
    }
}

 sessionProvider.Store("CurrentConnectionString", "Sample07Context");
uow.SetConnectionString(WebConfigurationManager.ConnectionStrings[_sessionProvider.Get<string>("CurrentConnectionString")].ConnectionString);

using System;
using System.Data.Entity;
using System.Web;
using EF_Sample07.DataLayer.Context;
using EF_Sample07.IoCConfig;
 
namespace EF_Sample07.WebFormsAppSample
{
    public class Global : HttpApplication
    {
        void Application_Start(object sender, EventArgs e)
        {
            initDatabases();
        }
 
        private static void initDatabases()
        {
            // defined in web.config
            string[] connectionStringNames =
            {
                "Sample07Context",
                "Database2012"
            };
 
            foreach (var connectionStringName in connectionStringNames)
            {
                Database.SetInitializer(
                    new MigrateDatabaseToLatestVersion<Sample07Context, Configuration>(connectionStringName));
 
                using (var ctx = new Sample07Context(connectionStringName))
                {
                    ctx.Database.Initialize(force: true);
                }
            }
        }
 
        void Application_EndRequest(object sender, EventArgs e)
        {
            SmObjectFactory.HttpContextDisposeAndClearAll();
        } 
    }
}

node -v

md \projects\node-edge-test1
cd \projects\node-edge-test1

npm install edge
npm install edge-sql

var edge = require('edge');

// The text in edge.func() is C# code
var helloWorld = edge.func('async (input) => { return input.ToString(); }');

helloWorld('Hello World!', function (error, result) {
    if (error) throw error;
    console.log(result);
});

node server.js

IF EXISTS(SELECT 1 FROM sys.tables WHERE object_id = OBJECT_ID('SampleUsers')) BEGIN; DROP TABLE SampleUsers; END; GO

CREATE TABLE SampleUsers ( Id INTEGER NOT NULL IDENTITY(1, 1), FirstName VARCHAR(255) NOT NULL, LastName VARCHAR(255) NOT NULL, Email VARCHAR(255) NOT NULL, CreateDate DATETIME NOT NULL DEFAULT(getdate()), PRIMARY KEY (Id) ); GO

INSERT INTO SampleUsers(FirstName,LastName,Email,CreateDate) VALUES('Orla','Sweeney','nunc@convallisincursus.ca','Apr 13, 2014');
INSERT INTO SampleUsers(FirstName,LastName,Email,CreateDate) VALUES('Zia','Pickett','porttitor.tellus.non@Duis.com','Aug 31, 2014');
INSERT INTO SampleUsers(FirstName,LastName,Email,CreateDate) VALUES('Justina','Ayala','neque.tellus.imperdiet@temporestac.com','Jul 28, 2014');
INSERT INTO SampleUsers(FirstName,LastName,Email,CreateDate) VALUES('Levi','Parrish','adipiscing.elit@velarcueu.com','Jun 21, 2014');
INSERT INTO SampleUsers(FirstName,LastName,Email,CreateDate) VALUES('Pearl','Warren','In@dignissimpharetra.org','Mar 3, 2014');

set EDGE_SQL_CONNECTION_STRING=Data Source=localhost;Initial Catalog=node-test;Integrated Security=True

SETX EDGE_SQL_CONNECTION_STRING "Data Source=localhost;Initial Catalog=node-test;Integrated Security=True"

var http = require('http');
var edge = require('edge');
var port = process.env.PORT || 8080;

var getTopUsers = edge.func('sql', function () {/*
    SELECT TOP 3 * FROM SampleUsers ORDER BY CreateDate DESC
*/});

function logError(err, res) {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.write("Error: " + err);
    res.end("");
}    

http.createServer(function (req, res) {
    res.writeHead(200, { 'Content-Type': 'text/html' });

    getTopUsers(null, function (error, result) {
        if (error) { logError(error, res); return; }
        if (result) {
            res.write("<ul>");
            result.forEach(function(user) {
                res.write("<li>" + user.FirstName + " " + user.LastName + ": " + user.Email + "</li>");
            });
            res.end("</ul>");
        }
        else {
        }
    });
}).listen(port);
console.log("Node server listening on port " + port);

node server-sql-query.js

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Threading.Tasks;

namespace EdgeSampleLibrary
{
     public class Sample1
    {
        public async Task<object> Invoke(object input)
        {
            // Edge marshalls data to .NET using an IDictionary<string, object>
            var payload = (IDictionary<string, object>) input;
            var pageNumber = (int) payload["pageNumber"];
            var pageSize = (int) payload["pageSize"];
            return await QueryUsers(pageNumber, pageSize);
        }

        public async Task<List<SampleUser>> QueryUsers(int pageNumber, int pageSize)
        {
            // Use the same connection string env variable
            var connectionString = Environment.GetEnvironmentVariable("EDGE_SQL_CONNECTION_STRING");
            if (connectionString == null)
                throw new ArgumentException("You must set the EDGE_SQL_CONNECTION_STRING environment variable.");

            // Paging the result set using a common table expression (CTE).
            // You may rather do this in a stored procedure or use an 
            // ORM that supports async.
            var sql = @"
DECLARE @RowStart int, @RowEnd int;
SET @RowStart = (@PageNumber - 1) * @PageSize + 1;
SET @RowEnd = @PageNumber * @PageSize;

WITH Paging AS
(
    SELECT  ROW_NUMBER() OVER (ORDER BY CreateDate DESC) AS RowNum,
            Id, FirstName, LastName, Email, CreateDate
    FROM    SampleUsers
)
SELECT  Id, FirstName, LastName, Email, CreateDate
FROM    Paging
WHERE   RowNum BETWEEN @RowStart AND @RowEnd
ORDER BY RowNum;
";
            var users = new List<SampleUser>();

            using (var cnx = new SqlConnection(connectionString))
            {
                using (var cmd = new SqlCommand(sql, cnx))
                {
                    await cnx.OpenAsync();

                    cmd.Parameters.Add(new SqlParameter("@PageNumber", SqlDbType.Int) { Value = pageNumber });
                    cmd.Parameters.Add(new SqlParameter("@PageSize", SqlDbType.Int) { Value = pageSize });

                    using (var reader = await cmd.ExecuteReaderAsync(CommandBehavior.CloseConnection))
                    {
                        while (await reader.ReadAsync())
                        {
                            var user = new SampleUser
                            {
                                Id = reader.GetInt32(0), 
                                FirstName = reader.GetString(1), 
                                LastName = reader.GetString(2), 
                                Email = reader.GetString(3), 
                                CreateDate = reader.GetDateTime(4)
                            };
                           users.Add(user);
                        }
                    }
                }
            }
            return users;
        } 
    }

    public class SampleUser
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Email { get; set; }
        public DateTime CreateDate { get; set; }
    }
}

[project]/bin/Debug/EdgeSampleLibrary.dll

var http = require('http');
var edge = require('edge');
var port = process.env.PORT || 8080;

// Set up the assembly to call from Node.js 
var querySample = edge.func({ assemblyFile: 'EdgeSampleLibrary.dll', typeName: 'EdgeSampleLibrary.Sample1', methodName: 'Invoke' });

function logError(err, res) { res.writeHead(200, { 'Content-Type': 'text/plain' }); res.write("Got error: " + err); res.end(""); }

http.createServer(function (req, res) { res.writeHead(200, { 'Content-Type': 'text/html' });

    // This is the data we will pass to .NET
    var data = { pageNumber: 1, pageSize: 3 };

    // Invoke the .NET function
    querySample(data, function (error, result) {
        if (error) { logError(error, res); return; }
        if (result) {
            res.write("<ul>");
            result.forEach(function(user) {
                res.write("<li>" + user.FirstName + " " + user.LastName + ": " + user.Email + "</li>");
            });
            res.end("</ul>");
        }
        else {
            res.end("No results");
        }
    });

}).listen(port);

console.log("Node server listening on port " + port);

node server-dotnet-query.js

public class EntityAudit<TEntity>
{
    [JsonProperty("type")]
    [JsonConverter(typeof(StringEnumConverter))]
    public EntityEventType EventType { get; set; }

    [JsonProperty("user", NullValueHandling = NullValueHandling.Include)]
    public int? ActorUserId { get; set; }

    [JsonProperty("at")]
    public DateTime ActDateTime { get; set; }

    [JsonProperty("sources")]
    public AuditSourceValues? AuditSourceValues { get; set; }

    [JsonProperty("newValues", NullValueHandling = NullValueHandling.Include)]
    public TEntity NewEntity { get; set; } = default!;

    public string? SerializeJson()
    {
        return JsonSerializer.Serialize(this, 
            options: new JsonSerializerOptions { WriteIndented = false, IgnoreNullValues = true }); 
    }
}

دقت کنید که این کلاس به صورت جنریک تعریف شده است تا اگر بعدا بخواهیم آن را Deserialize کنیم و مثلا از آن API بسازیم، یا استفاده‌ی خاصی را از آن داشته باشیم، به‌راحتی به Entity مد نظر تبدیل شود. در این مقاله فقط به ذخیره‌ی آن پرداخته می‌شود و استفاده از این فیلد که به راحتی و با کمک DbFunctionها در Entity Framework قابل انجام است به خواننده واگذار می‌شود. 

و سپس آن را به سیستم معرفی می‌کنیم:

services.AddDbContext<ATADbContext>((serviceProvider, options) =>
{
    options
        .UseSqlServer(...)

    // Interceptors
    var entityAuditProvider = serviceProvider.GetRequiredService<IEntityAuditProvider>();
    options.AddInterceptors(new AuditSaveChangesInterceptor(entityAuditProvider));

});

ولی روش گفته شده در این مقاله، همین عملیات را به صورت کاملتری و فقط بر روی یک ستون همان جدول انجام می‌دهد که باعث ذخیره‌ی دیتای کمتر، یکپارچگی بهتر و دسترسی‌پذیری و راحتی استفاده از آن می‌شود.

using System;
using System.Linq;
using System.Net;
using System.Text;
using HtmlAgilityPack;

namespace HapTests
{
    public class HtmlReader
    {
        public Action<string> ParseError { set; get; }

        public Func<HtmlNode, bool> ParserHtmlNode { set; get; }

        public void StartParsingHtml(Uri url)
        {
            using (var client = new WebClient { Encoding = Encoding.UTF8 })
            {
                client.Headers.Add("user-agent", "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)");
                StartParsingHtml(client.DownloadString(url));
            }
        }

        public void StartParsingHtml(string htmlContent)
        {
            if (string.IsNullOrWhiteSpace(htmlContent))
                throw new ArgumentNullException("content");

            var doc = new HtmlDocument
            {
                OptionCheckSyntax = true,
                OptionFixNestedTags = true,
                OptionAutoCloseOnEnd = true,
                OptionDefaultStreamEncoding = Encoding.UTF8
            };
            doc.LoadHtml(htmlContent);

            if (doc.ParseErrors != null && doc.ParseErrors.Any())
            {
                foreach (var error in doc.ParseErrors)
                {
                    if (ParseError != null)
                        ParseError(error.Code + " - " + error.Reason);
                }
            }

            if (!doc.DocumentNode.HasChildNodes)
                return;

            handleChildren(doc.DocumentNode.ChildNodes);
        }

        private void handleChildren(HtmlNodeCollection nodes)
        {
            foreach (var itm in nodes)
            {
                if (itm.Name.ToLower().Equals("html"))
                {
                    if (itm.Element("body") != null)
                        handleChildren(itm.Element("body").ChildNodes);
                }
                else
                    handleHtmlNode(itm);
            }
        }

        private void parserChildNodes(HtmlNode content)
        {
            foreach (var item in content.ChildNodes)
            {
                handleHtmlNode(item);
            }
        }

        private void handleHtmlNode(HtmlNode htmNode)
        {
            switch (htmNode.Name.ToLower())
            {
                case "html":
                case "body":
                    handleChildren(htmNode.ChildNodes);
                    break;

                default:
                    if (ParserHtmlNode == null)
                        throw new ArgumentNullException("ParserHtmlNode");

                    if (ParserHtmlNode(htmNode))
                        parserChildNodes(htmNode);

                    break;
            }
        }
    }
}

new HtmlReader
{
    ParseError = error => Console.WriteLine(error),
    ParserHtmlNode = htmlNode =>
    {
        //switch(htmlNode.Name) { }
        return true; //it's a nested node.
    }
}.StartParsingHtml(html);

using System;
using System.Diagnostics;
using System.IO;
using System.Text;
using HtmlAgilityPack;

namespace HapTests
{
    class Program
    {
        static void Main(string[] args)
        {
            var html = 
                @"<table width='750' border='0' style='font-size: 10pt; width: 736px' class='boxcar2 gerd'>
            <tbody><tr>
            <td height='70' colspan='4' class='boxcart1 gerd'>
            <iframe width='718' scrolling='no'>
            </iframe></td>
            </tr>
            <tr>
            <td height='70' colspan='4' class='boxcart1 gerd'>
    </td>
            </tr>
            <tr>
            <td width='193' height='36' class='boxcart2 gerd'>
            <a target='_self' href='Curr.cbi.2.php'>نرخ ارز مبادله ای بانک مرکزی</a></td>
            <td width='181' height='36' class='boxcart2 gerd'>
            <a target='_self' href='Curr.cbi.php'>نرخ ارز مرجع بانک مرکزی</a></td>
            <td width='149' height='36' class='boxcart2 gerd'>
            <a target='_self' href='curv.htm'>نمودار قیمت طلا</a></td>
            <td width='199' height='36' class='boxcart2 gerd'>
            <a target='_self' href='index.php'>قیمت طلا و سکه در بازار ایران</a></td>
            </tr>
            <tr>
            <td height='48' colspan='4' class='boxcart1 gerd'>
            <p dir='rtl'><span style='font-size: 13pt;'>تابلو آنلاین قیمت جهانی طلا و نقره ( دلار 
            )</span></p></td>
            </tr>
            <tr>
            <td height='57' colspan='2' class='boxcart1 gerd'>قیمت لحظه ای هر انس 
            نقره در بازارهای جهانی<br>
            <span style='font-size: 9pt;'>
            </span></td>
            <td height='57' colspan='2' class='boxcart1 gerd'>قیمت لحظه ای هر انس 
            طلا در بازارهای جهانی<br>
            <span style='font-size: 9pt;'>
            </span></td>
            </tr>
            <tr>
            <td height='48' colspan='4' class='boxcart1 gerd'>
            <p dir='rtl'><span style='font-size: 13pt'>تابلو آنلاین قیمت طلا ، سکه 
            و نقره در بازار ایران ( ریال )</span></p>
            </td>
            </tr>
            <tr>
            <td style='direction: rtl; font-size: 8pt' colspan='4'><div align='center'>
                            <table id='gold_tbl'><tbody><tr><th>قیمت طلا</th><th>قیمت زنده</th><th>تغییر</th>
                            <th>کمترین</th><th>بیشترین</th><th>زمان</th></tr><tr><td>انس طلا <sup>دلار</sup></td>
                            <td class='s0_1'>1,375.90</td><td class='c0_1 neg'>(-0.34%) -4.70</td>
                            <td class='l0_1'>1,374.90</td><td class='h0_1'>1,380.80</td><td class='z0_1 fa'>17:53</td>
                            </tr><tr><td>مثقال طلا</td><td class='s3_2'>5,290,000</td>
                            <td class='c3_2 pos'>(1.63%) 85,000</td><td class='l3_2'>5,200,000</td><td class='h3_2'>5,320,000</td><td class='z3_2 fa'>17:50</td></tr><tr><td>گرم طلای 18</td>
                            <td class='s3_3'>1,221,200</td><td class='c3_3 pos'>(1.63%) 19,600</td><td class='l3_3'>1,200,400</td><td class='h3_3'>1,228,100</td><td class='z3_3 fa'>17:50</td>
                            </tr><tr><td>انس نقره <sup>دلار</sup></td><td class='s0_5'>21.83</td><td class='c0_5'>(0.00%) 0.00</td><td class='l0_5'>21.67</td><td class='h0_5'>21.96</td>
                            <td class='z0_5 fa'>17:53</td></tr></tbody></table><br><table id='coin_tbl'><tbody><tr><th>سکه</th><th>قیمت زنده</th><th>تغییر</th><th>کمترین</th>
                            <th>بیشترین</th><th>ارزش طلا</th><th>زمان</th></tr><tr><td>بهار آزادی</td><td class='s3_10'>12,650,000</td><td class='c3_10 pos'>(2.68%) 330,000</td>
                            <td class='l3_10'>12,320,000</td><td class='h3_10'>12,650,000</td><td class='z4_10'>11,918,400</td><td class='z3_10 fa'>16:07</td></tr><tr><td>امامی</td>
                            <td class='s3_11'>12,960,000</td><td class='c3_11 pos'>(2.61%) 330,000</td><td class='l3_11'>12,630,000</td><td class='h3_11'>13,050,000</td><td class='z4_11'>11,918,400</td>
                            <td class='z3_11 fa'>17:43</td></tr><tr><td>نیم</td><td class='s3_12'>6,880,000</td><td class='c3_12 pos'>(2.69%) 180,000</td><td class='l3_12'>6,700,000</td>
                            <td class='h3_12'>6,900,000</td><td class='z4_12'>5,959,200</td><td class='z3_12 fa'>16:08</td></tr><tr><td>ربع</td><td class='s3_13'>4,250,000</td><td class='c3_13 pos'>(2.41%) 100,000</td>
                            <td class='l3_13'>4,150,000</td><td class='h3_13'>4,300,000</td><td class='z4_13'>2,978,100</td><td class='z3_13 fa'>17:42</td></tr><tr><td>گرمی</td><td class='s3_14'>2,940,000</td>   
                            <td class='c3_14 pos'>(3.16%) 90,000</td><td class='l3_14'>2,850,000</td><td class='h3_14'>2,940,000</td><td class='z4_14'>1,465,400</td><td class='z3_14 fa'>17:40</td></tr></tbody></table></div></td>
            </tr>
            </tbody></table>
                ";

            extractXPath(html);
            test(html);
        }

        /// <summary>
        /// Converts /#comment[1] to /comment()[1] 
        /// or /#text[1] to /text()[1]
        /// </summary>
        private static string GetValidXPath(string xpath)
        {
            var index = xpath.LastIndexOf("/");
            var lastPath = xpath.Substring(index);

            if (lastPath.Contains("#"))
            {
                xpath = xpath.Substring(0, index);
                lastPath = lastPath.Replace("#", "");
                lastPath = lastPath.Replace("[", "()[");
                xpath = xpath + lastPath;
            }

            return xpath;
        }

        private static void extractXPath(string html)
        {
            var sb = new StringBuilder();
            new HtmlReader
            {
                ParseError = error => Console.WriteLine(error),
                ParserHtmlNode = htmlNode =>
                {
                    if (htmlNode is HtmlTextNode)
                    {
                        sb.AppendLine("Text NodeName: " + htmlNode.Name.Trim());
                        sb.AppendLine("InnerText: " + htmlNode.InnerText.Trim());
                    }
                    else
                    {
                        sb.AppendLine("NodeName: " + htmlNode.Name.Trim());
                        var nodeText = new StringBuilder();
                        for (int i = 0; (i < htmlNode.OuterHtml.Length && htmlNode.OuterHtml[i] != '>'); i++)
                            nodeText.Append(htmlNode.OuterHtml[i]);

                        nodeText.Append(">");

                        sb.AppendLine("Node Start: " + nodeText.ToString());
                    }

                    sb.AppendLine("XPath: " + GetValidXPath(htmlNode.XPath.Trim()));
                    sb.AppendLine(Environment.NewLine);

                    return true; //it's a nested node.
                }
            }.StartParsingHtml(html);

            File.WriteAllText("xpath.txt", sb.ToString());
            Process.Start("xpath.txt");
        }

        private static void test(string html)
        {
            var doc = new HtmlDocument
            {
                OptionCheckSyntax = true,
                OptionFixNestedTags = true,
                OptionAutoCloseOnEnd = true,
                OptionDefaultStreamEncoding = Encoding.UTF8
            };
            doc.LoadHtml(html);
            var node = doc.DocumentNode.SelectSingleNode("/table[1]/tbody[1]/tr[7]/td[1]/div[1]/table[2]/tbody[1]/tr[6]/td[7]/text()[1]");
            Console.WriteLine(node.InnerText);
        }
    }
}

Text NodeName: #text
InnerText: 17:40
XPath: /table[1]/tbody[1]/tr[7]/td[1]/div[1]/table[2]/tbody[1]/tr[6]/td[7]/text()[1]

 @addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

{
    "dependencies": {
         //same as before
         "Microsoft.AspNetCore.Mvc.TagHelpers": "1.0.0",
         "Microsoft.AspNetCore.Razor.Runtime": "1.0.0",
         "Microsoft.AspNetCore.Razor.Tools": {
            "version": "1.0.0-preview2-final",
            "type": "build"
        }
    },
 
    "tools": {
         //same as before
        "Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview2-final"
    } 
}

 <a asp-controller="Home" asp-action="Index" asp-route-id="123">Home</a>

 <a asp-route="login">Login</a>

 <a asp-controller="Account"
   asp-action="Register"
   asp-protocol="https"
   asp-host="asepecificdomain.com"
   asp-fragment="fragment">Register</a>

 <form asp-controller="Account"
      asp-action="Login"
      asp-route-returnurl="@ViewBag.ReturnUrl"
      method="post" >
</form>

 <form action="/Account/Login?returnurl=%2FHome%2FAbout" method="post">

 <form asp-route="login"
      asp-route-returnurl="@ViewBag.ReturnUrl"
      method="post" >
</form>

 <script asp-src-include="~/app/**/*.js"></script>

 <script src="/app/app.js"></script>
<script src="/app/controllers/controller1.js"></script>
<script src="/app/controllers/controller2.js"></script>
<script src="/app/controllers/controller3.js"></script>
<script src="/app/controllers/controller4.js"></script>
<script src="/app/services/service1.js"></script>
<script src="/app/services/service2.js"></script>

 <script asp-src-include="~/app/**/*.js"
        asp-src-exclude="~/app/services/**/*.js">
</script>

 <link rel="stylesheet" href="//ajax.aspnetcdn.com/ajax/bootstrap/3.0.0/css/bootstrap.min.css"
      asp-fallback-href="~/lib/bootstrap/css/bootstrap.min.css"
      asp-fallback-test-class="hidden"
      asp-fallback-test-property="visibility"
      asp-fallback-test-value="hidden" />
 
<script src="//ajax.aspnetcdn.com/ajax/bootstrap/3.0.0/bootstrap.min.js"
        asp-fallback-src="~/lib/bootstrap/js/bootstrap.min.js"
        asp-fallback-test="window.jQuery">
</script>

 <link rel="stylesheet" href="~/css/site.min.css" asp-file-version="true"/>

 <link rel="stylesheet" href="/css/site.min.css?v=UdxKHVNJA5vb1EsG9O9uURFDfEE3j1E3DgwL6NiDGMc" />

 <img src="~/images/logo.png"
     alt="company logo"
     asp-file-version="true" />

 <img src="/images/logo.png?v=W2F5D366_nQ2fQqUk3URdgWy2ZekXjHzHJaY5yaiOOk"
     alt="company logo"/>

<environment names="Development">    
   <link rel="stylesheet" href="~/css/site1.css" />
   <link rel="stylesheet" href="~/css/site2.css" />
</environment>

<environment names="Staging,Production">
   <link rel="stylesheet" href="~/css/site.min.css" asp-file-version="true"/>
</environment>

public class CustomerViewModel
{
   public string Vehicle { get; set; }  
   public List<SelectListItem> Vehicles { get; set; }

 <select asp-for="Vehicle" asp-items="Model.Vehicles">
</select>