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
});

type [access-modifier] type-name [type-params] [access-modifier] ( parameter-list ) [ as identifier ] =
   [ class ]
     [ inherit base-type-name(base-constructor-args) ]
     [ let-bindings ]
     [ do-bindings ]
     member-list
      ...
   [ end ]

type [access-modifier] type-name1 ...
and [access-modifier] type-name2 ...
...

type Account(number : int, name : string) = class
    let mutable amount = 0m
   
end

let myAccount = new Account(123456, "Masoud")

type Account(number : int, name: string) = class
    let mutable amount = 0m
 
    member x.Number = number
    member x.Name= name
    member x.Amount = amount
 
    member x.Deposit(value) = amount <- amount + value
    member x.Withdraw(value) = amount <- amount - value
end

open System
 
type Account(number : int, name: string) = class
    let mutable amount = 0m
 
    member x.Number = number
    member x.Name= name
    member x.Amount = amount
 
    member x.Deposit(value) = amount <- amount + value
    member x.Withdraw(value) = amount <- amount - value
end



 let masoud= new Account(12345, "Masoud")
 let saeed = new Account(67890, "Saeed")
 
let transfer amount (source : Account) (target : Account) =
    source.Withdraw amount
    target.Deposit amount
 
let printAccount (x : Account) =
    printfn "x.Number: %i, x.Name: %s, x.Amount: %M" x.Number x.Name x.Amount
 
let main() =
    let printAccounts() =
        [masoud; saeed] |> Seq.iter printAccount
 
    printfn "\nInializing account"
    homer.Deposit 50M
    marge.Deposit 100M
    printAccounts()
 
    printfn "\nTransferring $30 from Masoud to Saeed"
    transfer 30M masoud saeed



    printAccounts()
 
    printfn "\nTransferring $75 from Saeed to Masoud"
    transfer 75M saeed masoud
    printAccounts()
 
main()

open System
open System.Net
 
type Stock(symbol : string) = class

    let mutable _symbol = String.Empty
    do
     //کد مورد نظر در این جا نوشته  میشود
end

open System

type MyType(a:int, b:int) as this =
    inherit Object()
    let x = 2*a
    let y = 2*b
    do printfn "Initializing object %d %d %d %d %d %d"
               a b x y (this.Prop1) (this.Prop2)
    static do printfn "Initializing MyType." 
    member this.Prop1 = 4*x
    member this.Prop2 = 4*y
    override this.ToString() = System.String.Format("{0} {1}", this.Prop1, this.Prop2)

let obj1 = new MyType(1, 2)

Initializing MyType.
Initializing object 1 2 2 4 8 16

type SomeClass(prop : int) = class
    member x.Prop = prop
    static member SomeStaticMethod = "This is a static method"
end

let instance = new SomeClass(5);;
instance.SomeStaticMethod;; 

output:
stdin(81,1): error FS0191: property 'SomeStaticMethod' is static.

SomeClass.SomeStaticMethod;; (* invoking static method *)

 member alias.PropertyName
        with get() = some-value
        and set(value) = some-assignment

type MyClass() = class
   let mutable num = 0 
    member x.Num
        with get() = num
        and set(value) = num <- value
end;;

public int Num
{
   get{return num;}
   set{num=value;}
}

type MyClass() = class
    let mutable num = 0
 
    member x.Num
        with get() = num
        and set(value) =
            if value > 10 || value < 0 then
                raise (new Exception("Values must be between 0 and 10"))
            else
                num <- value
end

type type-name = 
   interface
       inherits-decl 
       member-defns 
   end

type IPrintable =
   abstract member Print : unit -> unit

type SomeClass1(x: int, y: float) =
   interface IPrintable with 
      member this.Print() = printfn "%d %f" x y

let instance = new SomeClass1(10,20)
instance.Print//فراخوانی این متد باعث ایجاد خطای کامپایلری می‌شود.

let instance = new SomeClass1(10,20) 
let instanceCast = instance :> IPrintable// استفاده از (<:)  برای عملیات تبدیل کلاس به اینترفیس
instanceCast.Print

type Interface1 =
    abstract member Method1 : int -> int

type Interface2 =
    abstract member Method2 : int -> int

type Interface3 =
    inherit Interface1
    inherit Interface2
    abstract member Method3 : int -> int

type MyClass() =
    interface Interface3 with 
        member this.Method1(n) = 2 * n
        member this.Method2(n) = n + 100
        member this.Method3(n) = n / 10

let instance = new MyClass()
let instanceToCast = instance :> Interface3
instanceToCast.Method3 10

[<AbstractClass>]
type [ accessibility-modifier ] abstract-class-name =
    [ inherit base-class-or-interface-name ]
    [ abstract-member-declarations-and-member-definitions ]

    abstract member member-name : type-signature

[<AbstractClass>]
type Shape(x0 : float, y0 : float) =
    let mutable x, y = x0, y0
    let mutable rotAngle = 0.0

    abstract Area : float with get
    abstract Perimeter : float  with get
    abstract Name : string with get

type Square(x, y,SideLength) =
    inherit Shape(x, y)





   override this.Area = this.SideLength * this.SideLength
    override this.Perimeter = this.SideLength * 4.
    override this.Name = "Square"

type Circle(x, y, radius) =
    inherit Shape(x, y)



    let PI = 3.141592654
    member this.Radius = radius
    override this.Area = PI * this.Radius * this.Radius
    override this.Perimeter = 2. * PI * this.Radius

[ attributes ]
type [accessibility-modifier] type-name =
   struct
      type-definition-elements
   end

//یا به صورت زیر

[ attributes ]
[<StructAttribute>]
type [accessibility-modifier] type-name =
   type-definition-elements

type Point3D =
   struct 
      val x: float
      val y: float
      val z: float
   end

type Point2D =
   struct 
      val X: float
      val Y: float
      new(x: float, y: float) = { X = x; Y = y }
   end

An open source checklist of resources designed to improve your online privacy and security. Check things off to keep track as you go. 

There are two things you should keep in mind:
 1. Don't wrap asynchronous tasks in another call to Task.Run().
 2. Don't use asynchronous wrappers over synchronous calls.

30 Day Vanilla JS Coding Challenge
Build 30 things in 30 days with 30 tutorials
No Frameworks×No Compilers×No Libraries×No Boilerplate 

1. Custom Windows Layouts
2. Better Code Editor
3. Shared Project – “All the Things!”
4. IntelliSense for Bower and NPM
5. Debug Lambdas

...

Tuple does many things KeyValuePair does not. Tuples are comparable, they implement the IComparable and IStructuralEquatable interfaces, so it makes compare two tuple

...

    <asp:GridView ID="gvCities"
                runat="server"
                AutoGenerateColumns="False"
                ItemType="WebApplication3.City"
                SelectMethod="GetAllCities">
                <Columns>
                    <asp:TemplateField HeaderText="نام">
                        <ItemTemplate><%#: Item.Name %></ItemTemplate>
                    </asp:TemplateField>
                </Columns>
     </asp:GridView>

 public IQueryable<City> GetAllCities()
        {
            var context = new EFContext();
            var q = from c in context.City
                    orderby c.Name
                    select c;
            return q;
        }

 gvCities.DataBind();

   <asp:GridView ID="gvCities" 
                runat="server" 
                AutoGenerateColumns="False"
                AllowPaging="True" 
                PageSize="10" 
                ItemType="WebApplication3.City" 
                SelectMethod="GetAllCities">
                 <Columns>
                    <asp:TemplateField HeaderText="نام">
                        <ItemTemplate><%#: Item.Name %></ItemTemplate>
                    </asp:TemplateField>
                </Columns>
  </asp:GridView>

 public IQueryable<City> GetAllCities(int startRowIndex, int maximumRows, out int totalRowCount)
 {
        var context = new EFContext();
        var q = from c in context.City
                    select c;

        totalRowCount = q.Count();

        return q.OrderBy(x=>x.Name).Skip(startRowIndex).Take(maximumRows);
 }