app.UseMvcWithDefaultRoute();

    public static IApplicationBuilder UseMvcWithDefaultRoute(this IApplicationBuilder app)
    {
      if (app == null)
        throw new ArgumentNullException("app");
      return app.UseMvc((Action<IRouteBuilder>) (routes => routes.MapRoute("default", "{controller=Home}/{action=Index}/{id?}")));
    }

 [Route("[controller]/[action]")]

namespace Core1RtmEmptyTest.Controllers
{
  public class HomeController
  {
   public string Index()
   {
    return "Running a POCO controller!";
   }
  }
}

app.UseMvc(routes =>
{
  routes.MapRoute(
   name: "default",
   template: "{controller=Home}/{action=Index}/{id?}");
});

using Microsoft.AspNetCore.Mvc;
 
namespace Core1RtmEmptyTest.Controllers
{
  public class AboutController : Controller
  {
   public ActionResult Hello()
   {
    return Content("Hello from DNT!");
   }
 
   public ActionResult SiteName()
   {
    return Content("DNT");
   }
  }
}

using Microsoft.AspNetCore.Mvc;
 
namespace Core1RtmEmptyTest.Controllers
{
  [Route("About")]
  public class AboutController : Controller
  {
   [Route("")]
   public ActionResult Hello()
   {
    return Content("Hello from DNT!");
   }
 
   [Route("SiteName")]
   public ActionResult SiteName()
   {
    return Content("DNT");
   }
  }
}

 AmbiguousActionException: Multiple actions matched. The following actions matched route data and had all constraints satisfied:

Core1RtmEmptyTest.Controllers.AboutController.Hello (Core1RtmEmptyTest)
Core1RtmEmptyTest.Controllers.AboutController.SiteName (Core1RtmEmptyTest)

using Microsoft.AspNetCore.Mvc;
 
namespace Core1RtmEmptyTest.Controllers
{
  [Route("[controller]")]
  public class AboutController : Controller
  {
   [Route("")]
   public ActionResult Hello()
   {
    return Content("Hello from DNT!");
   }
 
   [Route("[action]")]
   public ActionResult SiteName()
   {
    return Content("DNT");
   }
  }
}

 [Route("api/[controller]")]

//[Route("/Users/{userid}")]
[Route("Users/{userid}")]
public IActionResult GetUsers(int userId)
{
    return Json(new { userId = userId });
}

[Route("/Users/{userid:int?}")]

 [Route("Users/{userid:int}")]

 [Route("/Users/{userid:int:max(1000):min(10)}")]

 [Route("/Users/{userid:int}", Name="GetUserById")]

 string uri = Url.Link("GetUserById", new { userid = 1 });

 [Route("/Users/{userid:int}", Name = "GetUserById", Order = 1)]

using System;
using System.Globalization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;
 
namespace Core1RtmEmptyTest
{
  public class CustomRouteConstraint : IRouteConstraint
  {
   public bool Match(HttpContext httpContext, IRouter route, string routeKey, RouteValueDictionary values,
    RouteDirection routeDirection)
   {
    object value;
    if (!values.TryGetValue(routeKey, out value) || value == null)
    {
      return false;
    }
 
    long longValue;
    if (value is long)
    {
      longValue = (long)value;
      return longValue != 10;
    }
 
    var valueString = Convert.ToString(value, CultureInfo.InvariantCulture);
    if (long.TryParse(valueString, NumberStyles.Integer,
      CultureInfo.InvariantCulture, out longValue))
    {
      return longValue != 10;
    }
    return false;
   }
  }
}

public void ConfigureServices(IServiceCollection services)
{
    services.AddRouting(options =>options.ConstraintMap.Add("Custom", typeof(CustomRouteConstraint)));

 [Route("/Users/{userid:int:custom}")]

app.UseMvc(routes =>
{
  routes.MapRoute(
   name: "default",
   template: "{controller=Home}/{action=Index}/{id?}");
 
  routes.MapRoute(
   name: "spa-fallback",
   template: "{*url}",
   defaults: new { controller = "Home", action = "Index" });
});

{
    "dependencies": {
       //same as before  
       "Microsoft.AspNetCore.SpaServices": "1.0.0-beta-000007"
 },

app.UseMvc(routes =>
{
  routes.MapRoute(
   name: "default",
   template: "{controller=Home}/{action=Index}/{id?}");
 
  routes.MapSpaFallbackRoute("spa-fallback", new { controller = "Home", action = "Index" });
});

// Serve wwwroot as root
app.UseFileServer();
 
// Serve /node_modules as a separate root (for packages that use other npm modules client side)
app.UseFileServer(new FileServerOptions
{
  // Set root of file server
  FileProvider = new PhysicalFileProvider(Path.Combine(Directory.GetCurrentDirectory(), "node_modules")),
  // Only react to requests that match this path
  RequestPath = "/node_modules",
  // Don't expose file system
  EnableDirectoryBrowsing = false
});

 public int Sum(int a, int b)
{
     return a + b;
}

 public static IEnumerable SomeNumbers()
{
     yield return 3;
     yield return 5;
     yield return 8;
}

static void Main()
{
    foreach (int number in SomeNumbers())
    {
        Console.Write(number.ToString() + " ");
    }
    // Output: 3 5 8
    Console.ReadKey();
}

 public static IEnumerable SomeNumbers()
{
   yield return 3;
   yield return 5;
   yield return 8;
   yeild break;
}

static void Main()
{
  DaysOfTheWeek days = new DaysOfTheWeek();
  foreach (string day in days)
    {
        Console.Write(day + " ");
    }
    // Output: Sun Mon Tue Wed Thu Fri Sat
    Console.ReadKey();
}

public class DaysOfTheWeek : IEnumerable
{
  private string[] days = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
  public IEnumerator GetEnumerator()
    {
        for (int index = 0; index < days.Length; index++)
        {
            // Yield each day of the week. 
            yield return days[index];
        }
    }
}

  public bool IsDeleted { get; set; }

public interface ISoftDelete
{
    bool IsDeleted { get; set; }
}

public class Post :ISoftDelete
{
}

where (IsDeleted=false && ...)

public static class EntityFrameworkExtentions
{
    public static ObservableCollection<TEntity> Alive<TEntity>(this DbSet<TEntity> set)
        where TEntity : class, ISoftDelete
    {
        var data = set.Where(e => e.IsDeleted == false);
        return new ObservableCollection<TEntity>(data);
    }
}

Install-Package EntityFramework.DynamicFilters

modelBuilder.Filter("IsDeleted", (ISoftDelete d) => d.IsDeleted, false);

The DELETE statement conflicted with the REFERENCE constraint ....

public bool CanDelete(user model)
{
return !model.posts.Any() &&  ! model.news.Any();
}

[AttributeUsage(AttributeTargets.Property)]
public class MustBeEmptyToDeleteAttribute : Attribute { }

public class User
{
    public int Id { get; set; }
    public bool IsDeleted { get; set; }

    [MustBeEmptyToDelete] public virtual ICollection<Post> Posts { get; set; }
    [MustBeEmptyToDelete] public virtual ICollection<File> Files { get; set; }
    // etc...
}

public static class EntityExtensions
{
    public static bool CanDelete(this object entity)
    {
        return entity.GetType().GetProperties()
            .Where(x => x.IsDefined(typeof(MustBeEmptyToDeleteAttribute)))
            .Select(x => x.GetValue(entity))
            .OfType<IEnumerable<object>>()
            .All(x => !x.Any());
    }

 public void MarkAsSoftDeleted<TEntity>(TEntity entity) where TEntity : ISoftDelete
        {
            Entry(entity).State = EntityState.Modified;
           // set IsDelete=true 
          // here you can set other logs like who deleted ,when ,...
      }

 public void MarkAsDeleted<TEntity>(TEntity entity) where TEntity : class
    {
            Entry(entity).State = EntityState.Deleted;
    }

void Application_Start(object sender, EventArgs e)
{
    RouteTable.Routes.MapHttpRoute(
        name: "DefaultApi",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = System.Web.Http.RouteParameter.Optional }
        );
}

var person = { type: '', name:'No Name' };
var employee = {  };

console.log('Before Inheritance -> employee.name = ' + employee.name);

employee.__proto__ = person;

employee.name = 'farid';
console.log('After Assiginig -> employee.name = ' + employee.name);
console.log('After Assiginig -> person.name = ' + person.name);

<a class="btn btn-primary" href="#" role="button">Link</a>
<button class="btn btn-primary" type="submit">Button</button>
<input class="btn btn-primary" type="submit" value="Input">

<button class="btn btn-primary">Primary</button>
<button class="btn btn-secondary">Secondary</button>
<button class="btn btn-success">Success</button>
<button class="btn btn-danger">Danger</button>
<button class="btn btn-warning">Warning</button>
<button class="btn btn-info">Info</button>
<button class="btn btn-light">Light</button>
<button class="btn btn-dark">Dark</button>

<button class="btn btn-outline-primary">Primary</button>
<button class="btn btn-outline-secondary">Secondary</button>
<button class="btn btn-outline-success">Success</button>
<button class="btn btn-outline-danger">Danger</button>
<button class="btn btn-outline-warning">Warning</button>
<button class="btn btn-outline-info">Info</button>
<button class="btn btn-outline-light">Light</button>
<button class="btn btn-outline-dark">Dark</button>

<button class="btn btn-primary">Default</button>
<button class="btn btn-primary btn-lg">Large</button>
<button class="btn btn-primary btn-sm">Small</button>
<button class="btn btn-primary btn-block">Block</button>

<h2>States</h2>
<h3>Active</h3>
<button class="btn btn-primary active">Active Button</button>

<h3>Disabled</h3>
<button class="btn btn-primary disabled">Disabled Button</button>
<a class="btn btn-primary disabled" href="#">Disabled Link Button</a>

<div class="btn-toolbar" aria-label="All pets">
    <div class="btn-group mb-2 mr-2" aria-label="Common pets">
        <button type="button" class="btn btn-primary active">Cat</button>
        <button type="button" class="btn btn-primary">Dog</button>
        <button type="button" class="btn btn-primary">Fish</button>
        <button type="button" class="btn btn-primary">Bird</button>
    </div>

    <div class="btn-group mb-2" aria-label="Exotic pets">
        <button type="button" class="btn btn-primary">Amphibian</button>
        <button type="button" class="btn btn-primary active">Reptile</button>
        <button type="button" class="btn btn-primary">Other</button>
    </div>
</div>

<div class="btn-group-vertical mb-2" aria-label="Exotic pets">
    <button type="button" class="btn btn-primary">Amphibian</button>
    <button type="button" class="btn btn-primary active">Reptile</button>
    <button type="button" class="btn btn-primary">Other</button>
</div>

    <div class="container">
        <div class="row">
            <section class="col-12">
                <h1>Our Commitment <span class="badge badge-info">to you</span></h1>
                <h3>Grooming <span class="badge badge-danger badge-pill">new</span></h3>
            </section>
        </div><!-- row -->
    </div><!-- content container -->

<ul class="list-group mb-3">
    <li class="list-group-item active">Grooming</li>
    <li class="list-group-item list-group-item-action">
        General Health
    </li>
    <li class="list-group-item list-group-item-action">Nutrition</li>
    <li class="list-group-item list-group-item-action">
        Pest Control
    </li>
    <li class="list-group-item list-group-item-action">Vaccinations</li>
</ul>

<div class="list-group mb-3">
    <a class="list-group-item active" href="#">Grooming</a>
    <a class="list-group-item list-group-item-action list-group-item-success"
        href="#">Nutrition</a>
    <a class="list-group-item list-group-item-action  list-group-item-info"
        href="#">
        Pest Control
    </a>
    <a class="list-group-item list-group-item-action  list-group-item-warning"
        href="#">Vaccinations</a>
</div>

<li class="list-group-item list-group-item-action d-flex justify-content-between align-items-center">
    Nutrition
    <span class="badge badge-info badge-pill">12</span>
</li>

public class User
    {       
        public Int64 UserId { get; set; }       
        public String UserName { get; set; }
     }        

 public interface IUserService
    {        
        int GetCustomerCount();
        List<User> GetCustomers(int StartIndex, int PageSize);
    }

public class ImplUserService : IUserService
    {
        IUnitOfWork _uow;
        IDbSet<User> _user;

        public ImplUserService(IUnitOfWork uow)
        {
            _uow = uow;
            _user = uow.Set<User>();
        }

        public int GetCustomerCount()
        {
            int totalCount = _user.ToList().Count;             
            return totalCount;
        }

        public List<User> GetCustomers(int StartIndex, int PageSize)
        {
            return _user.OrderBy(i => i.UserId).Skip(StartIndex).Take(PageSize).ToList();
        }
  }

<asp:ListView ID="ListView1" runat="server" DataSourceID="ObjectDataSource1">
            <ItemTemplate>
                <tr style="background-color: #DCDCDC; color: #000000;">
                    <td>
                        <asp:Label ID="UserIdLabel" runat="server" Text='<%# Eval("UserId") %>' />
                    </td>
                    <td>
                        <asp:Label ID="UserNameLabel" runat="server" Text='<%# Eval("UserName") %>' />
                    </td>
                </tr>
            </ItemTemplate>
            
            
            <LayoutTemplate>
                <table runat="server">
                    <tr runat="server">
                        <td runat="server">
                            <table id="itemPlaceholderContainer" runat="server" border="1" style="background-color: #FFFFFF;
                                border-collapse: collapse; border-color: #999999; border-style: none; border-width: 1px;">
                                <tr runat="server" style="background-color: #DCDCDC; color: #000000;">
                                    <th runat="server">
                                        UserId
                                    </th>
                                    <th runat="server">
                                        UserName
                                    </th>
                                </tr>
                                <tr id="itemPlaceholder" runat="server">
                                </tr>
                            </table>
                        </td>
                    </tr>
                    <tr runat="server">
                        <td runat="server" style="text-align: center; background-color: #CCCCCC;
                            color: #000000;">
                            <asp:DataPager ID="DataPager1" runat="server" PageSize="2">
                                <Fields>
                                    <asp:NextPreviousPagerField ButtonType="Button" ShowFirstPageButton="True" ShowNextPageButton="False"
                                        ShowPreviousPageButton="False" />
                                    <asp:NumericPagerField />
                                    <asp:NextPreviousPagerField ButtonType="Button" ShowLastPageButton="True" ShowNextPageButton="False"
                                        ShowPreviousPageButton="False" />
                                </Fields>
                            </asp:DataPager>
                        </td>
                    </tr>
                </table>
            </LayoutTemplate>                        
        </asp:ListView>

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server" EnablePaging="True" SelectCountMethod="GetCustomerCount"
            SelectMethod="GetCustomers" TypeName="UserService.ImplUserService" EnableViewState="False"
            MaximumRowsParameterName="PageSize" StartRowIndexParameterName="StartIndex">

protected void ObjectDataSource1_ObjectCreating(object sender, ObjectDataSourceEventArgs e)
        {            
            e.ObjectInstance = ObjectFactory.GetInstance<IUserService>();            
        }

<?xml version="1.0" encoding="utf-8"?>
<license id="17d46246-a6cb-4196-98a0-ff6fc08cb67f" expiration="2012-06-12T00:00:00.0000000" type="Trial" prof="EFProf">
  <name>MyName</name>
  <Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
    <SignedInfo>
      <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
      <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
      <Reference URI="">
        <Transforms>
          <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
        </Transforms>
        <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
        <DigestValue>b8N0bDE4gTakfdGKtzDflmmyyXI=</DigestValue>
      </Reference>
    </SignedInfo>
    <SignatureValue>IPELgc9BbkD8smXSe0sGqp5vS57CtZo9ME2ZfXSq/thVu...=</SignatureValue>
  </Signature>
</license>

        public static string CreateRSAKeyPair(int dwKeySize = 1024)
        {
            using (var provider = new RSACryptoServiceProvider(dwKeySize))
            {
                return provider.ToXmlString(includePrivateParameters: true);
            }
        }

namespace SignedXmlSample
{
    public enum LicenseType
    {
        None,
        Trial,
        Standard,
        Personal
    }
}

using System;
using System.Xml.Serialization;

namespace SignedXmlSample
{
    public class License
    {
        [XmlAttribute]
        public Guid Id { set; get; }
        
        public string Domain { set; get; }

        [XmlAttribute]
        public string IssuedTo { set; get; }

        [XmlAttribute]
        public DateTime Expiration { set; get; }

        [XmlAttribute]
        public LicenseType Type { set; get; }
    }
}

using System;
using System.IO;
using System.Security.Cryptography; // needs a ref. to `System.Security.dll` asm.
using System.Security.Cryptography.Xml;
using System.Text;
using System.Xml;
using System.Xml.Serialization;

namespace SignedXmlSample
{
    public static class LicenseGenerator
    {
        public static string CreateLicense(string licensePrivateKey, License licenseData)
        {
            using (var provider = new RSACryptoServiceProvider())
            {
                provider.FromXmlString(licensePrivateKey);
                var xmlDocument = createXmlDocument(licenseData);
                var xmlDigitalSignature = getXmlDigitalSignature(xmlDocument, provider);
                appendDigitalSignature(xmlDocument, xmlDigitalSignature);
                return xmlDocumentToString(xmlDocument);
            }
        }

        public static string CreateRSAKeyPair(int dwKeySize = 1024)
        {
            using (var provider = new RSACryptoServiceProvider(dwKeySize))
            {
                return provider.ToXmlString(includePrivateParameters: true);
            }
        }

        public static License ReadLicense(string licensePublicKey, string xmlFileContent)
        {
            var doc = new XmlDocument();
            doc.LoadXml(xmlFileContent);

            using (var provider = new RSACryptoServiceProvider())
            {
                provider.FromXmlString(licensePublicKey);

                var nsmgr = new XmlNamespaceManager(doc.NameTable);
                nsmgr.AddNamespace("sig", "http://www.w3.org/2000/09/xmldsig#");

                var xml = new SignedXml(doc);
                var signatureNode = (XmlElement)doc.SelectSingleNode("//sig:Signature", nsmgr);
                if (signatureNode == null)
                    throw new InvalidOperationException("This license file is not signed.");

                xml.LoadXml(signatureNode);
                if (!xml.CheckSignature(provider))
                    throw new InvalidOperationException("This license file is not valid.");

                var ourXml = xml.GetXml();
                if (ourXml.OwnerDocument == null || ourXml.OwnerDocument.DocumentElement == null)
                    throw new InvalidOperationException("This license file is coruppted.");

                using (var reader = new XmlNodeReader(ourXml.OwnerDocument.DocumentElement))
                {
                    var xmlSerializer = new XmlSerializer(typeof(License));
                    return (License)xmlSerializer.Deserialize(reader);
                }
            }
        }

        private static void appendDigitalSignature(XmlDocument xmlDocument, XmlNode xmlDigitalSignature)
        {
            xmlDocument.DocumentElement.AppendChild(xmlDocument.ImportNode(xmlDigitalSignature, true));
        }

        private static XmlDocument createXmlDocument(License licenseData)
        {
            var serializer = new XmlSerializer(licenseData.GetType());
            var sb = new StringBuilder();
            using (var writer = new StringWriter(sb))
            {
                var ns = new XmlSerializerNamespaces(); ns.Add("", "");
                serializer.Serialize(writer, licenseData, ns);
                var doc = new XmlDocument();
                doc.LoadXml(sb.ToString());
                return doc;
            }
        }

        private static XmlElement getXmlDigitalSignature(XmlDocument xmlDocument, AsymmetricAlgorithm key)
        {
            var xml = new SignedXml(xmlDocument) { SigningKey = key };
            var reference = new Reference { Uri = "" };
            reference.AddTransform(new XmlDsigEnvelopedSignatureTransform());
            xml.AddReference(reference);
            xml.ComputeSignature();
            return xml.GetXml();
        }

        private static string xmlDocumentToString(XmlDocument xmlDocument)
        {
            using (var ms = new MemoryStream())
            {
                var settings = new XmlWriterSettings { Indent = true, Encoding = Encoding.UTF8 };
                var xmlWriter = XmlWriter.Create(ms, settings);
                xmlDocument.Save(xmlWriter);
                ms.Position = 0;
                return new StreamReader(ms).ReadToEnd();
            }
        }
    }
}

using System;
using System.IO;

namespace SignedXmlSample
{
    class Program
    {
        static void Main(string[] args)
        {
            //Console.WriteLine(LicenseGenerator.CreateRSAKeyPair());
            writeLicense();            
            readLicense();

            Console.WriteLine("Press a key...");
            Console.ReadKey();
        }

        private static void readLicense()
        {
            var xml = File.ReadAllText("License.xml");
            const string publicKey = @"<RSAKeyValue>
                                    <Modulus>
                                        mBNKFIc/LkMfaXvLlB/+6EujPkx3vBOvLu8jdESDSQLisT8K96RaDMD1ORmdw2XNdMw/6ZBuJjLhoY13qCU9t7biuL3SIxr858oJ1RLM4PKhA/wVDcYnJXmAUuOyxP/vfvb798o6zAC1R2QWuzG+yJQR7bFmbKH0tXF/NOcSgbc=
                                    </Modulus>
                                    <Exponent>
                                        AQAB
                                    </Exponent>
                                 </RSAKeyValue>";

            var result = LicenseGenerator.ReadLicense(publicKey, xml);

            Console.WriteLine(result.Domain);
            Console.WriteLine(result.IssuedTo);
        }

        private static void writeLicense()
        {
            const string rsaData = @"<RSAKeyValue>
                    <Modulus>
                        mBNKFIc/LkMfaXvLlB/+6EujPkx3vBOvLu8jdESDSQLisT8K96RaDMD1ORmdw2XNdMw/6ZBuJjLhoY13qCU9t7biuL3SIxr858oJ1RLM4PKhA/wVDcYnJXmAUuOyxP/vfvb798o6zAC1R2QWuzG+yJQR7bFmbKH0tXF/NOcSgbc=
                    </Modulus>
                    <Exponent>
                        AQAB
                    </Exponent>
                    <P>
                        xwPKN77EcolMTD2O2Csv6k9Y4aen8UBVYjeQ4PtrNGz0Zx6I1MxLEFzRpiKC/Ney3xKg0Icwj0ebAQ04d5+HAQ==
                    </P>
                    <Q>
                        w568t0Xe6OBUfCyAuo7tTv4eLgczHntVLpjjcxdUksdVw7NJtlnOLApJVJ+U6/85Z7Ji+eVhuN91yn04pQkAtw==
                    </Q>
                    <DP>
                        svkEjRdA4WP5uoKNiHdmMshCvUQh8wKRBq/D2aAgq9fj/yxlj0FdrAxc+ZQFyk5MbPH6ry00jVWu3sY95s4PAQ==
                    </DP>
                    <DQ>
                        WcRsIUYk5oSbAGiDohiYeZlPTBvtr101V669IUFhhAGJL8cEWnOXksodoIGimzGBrD5GARrr3yRcL1GLPuCEvQ==
                    </DQ>
                    <InverseQ>
                        wIbuKBZSCioG6MHdT1jxlv6U1+Y3TX9sHED9PqGzWWpVGA+xFJmQUxoFf/SvHzwbBlXnG0DLqUvxEv+BkEid2w==
                    </InverseQ>
                    <D>                        Yk21yWdT1BfXqlw30NyN7qNWNuM/Uvh2eaRkCrhvFTckSucxs7st6qig2/RPIwwfr6yIc/bE/TRO3huQicTpC2W3aXsBI9822OOX4BdWCec2txXpSkbZW24moXu+OSHfAdYoOEN6ocR7tAGykIqENshRO7HvONJsOE5+1kF2GAE=
                    </D>
                  </RSAKeyValue>";

            string data = LicenseGenerator.CreateLicense(
                                                rsaData,
                                                new License
                                                {
                                                     Id = Guid.NewGuid(),
                                                     Domain = "dotnettips.info",
                                                     Expiration = DateTime.Now.AddYears(2),
                                                     IssuedTo = "VahidN",
                                                     Type = LicenseType.Standard
                                                });
            File.WriteAllText("License.xml", data);
        }
    }
}