یعنی اگر شما دارید نوع جدیدی را در یک زبان ایجاد می‌کنید که قصد دارید در یک زبان دیگر استفاده شود، نباید از امتیازات ویژه‌ای که آن زبان در اختیار شما می‌گذارد و به بیان بهتر CLS آن‌ها را پشتیبانی نمی‌کند، استفاده کنید؛ چرا که کد شما ممکن است در زبان دیگر مورد استفاده قرار نگیرد.

using System;

// Tell compiler to check for CLS compliance
[assembly: CLSCompliant(true)]

namespace SomeLibrary {

// Warnings appear because the class is public
public sealed class SomeLibraryType {

// Warning: Return type of 'SomeLibrary.SomeLibraryType.Abc()'
// is not CLS­compliant
public UInt32 Abc() { return 0; }

// Warning: Identifier 'SomeLibrary.SomeLibraryType.abc()'
// differing only in case is not CLS­compliant
public void abc() { }

// No warning: this method is private
private UInt32 ABC() { return 0; }
}
}

class Animal

var Animal;
Animal = (function() {
  function Animal() {}
  return Animal;
})();

animal = new Animal

class Animal
  constructor: (name) ->
    @name = name

var Animal;
Animal = (function() {
  function Animal(name) {
    this.name = name;
  }
  return Animal;
})();

class Animal
  constructor: (@name) ->

animal = new Animal "Cat"
alert "Animal is a #{animal.name}"

class Animal
  price: 5

  sell: (customer) ->

animal = new Animal
animal.sell(new Customer)

var Animal, animal;

Animal = (function() {
  function Animal() {}

  Animal.prototype.price = 5;

  Animal.prototype.sell = function(customer) {};

  return Animal;

})();

animal = new Animal;
animal.sell(new Customer);

class Animal
  this.find = (name) ->

Animal.find("Dog")

class Animal
  @find: (name) ->

Animal.find("Dog")

var Animal;

Animal = (function() {
  function Animal() {}

  Animal.find = function(name) {};

  return Animal;

})();

Animal.find("Dog");

1. ساده و انعطاف پذیر
   
2. سورس باز بودن 
   
3. امکان استفاده در سیستم‌های با داده‌های رابطه ای و غیر رابطه ای
   
4. امکان استفاده از داده‌ها با منابع ای که آدرس پذیر هستند یعنی  دسترسی از طریق Url
   
5. امکان دسترسی هر نوع گیرنده ای به داده ها
   
6. امکان نمایش خروجی با فرمت Json  یا Xml 
   
7. ...

همانطور که میبینید گره دوم که "پوشه چهارم45" نام دارد شامل سه فرزند است که در رشته داده شده با عنوان item شناخته شده است. حال باید این رشته با برنامه نویسی سی شارپ جداسازی کرد :

string serialized;
Dictionary<int, int> numbers = new Dictionary<int, int>();   

public ActionResult SaveMenu(string serial)
        {
            var newfolders = new List<Folder>();
            serialized = serial;
            calculte_serialized(0);
            return RedirectToAction("Index");
        }

void calculte_serialized(int parent)
        {
            while (serialized.Length > 0)
            {
                var id_index=serialized.IndexOf("id");
                if (id_index == -1)
                {
                    return;
                }
                serialized = serialized.Substring(id_index + 5);
                var quote_index = serialized.IndexOf("\"");
                var id=serialized.Substring(0, quote_index);
                numbers.Add(int.Parse(id), parent);
                serialized = serialized.Substring(quote_index);
                var condition = serialized.Substring(0,3);
                switch (condition)
                {
                    case "\"},":
                        break;
                    case "\",\"":
                        calculte_serialized(int.Parse(id));
                        break;
                    case "\"}]":
                        return;
                        break;
                    default:
                        break;
                }
            }
        }

calculte_serialized با گرفتن 0 کار خود را شروع میکند یعنی از گره هایی که پدر ندارند و تمام id‌ها را همراه با پدرشان در یک دیکشنری میریزد و هرکجا که به فرزندی برخورد به صورت بازگشتی فراخوانی میشود. پس از اجرای کامل آن ما درخت را در یک دیکشنری به صورت عنصرهای مجزا در اختیار داریم که میتوانیم در پایگاه داده ذخیره کنیم.

    public class Bill
    {
        public int Id { set; get; }
        public string Name { set; get; }

        public virtual ICollection<Transaction> Transactions { set; get; }
    }

    public class Transaction
    {
        public int Id { set; get; }
        public DateTime AddDate { set; get; }
        public int Amount { set; get; }

        [ForeignKey("BillId")]
        public virtual Bill Bill { set; get; }
        public int BillId { set; get; }
    }

    public class MyContext : DbContext
    {
        public DbSet<Bill> Bills { get; set; }
        public DbSet<Transaction> Transactions { get; set; }
    }

    public class Configuration : DbMigrationsConfiguration<MyContext>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = true;
            AutomaticMigrationDataLossAllowed = true;
        }

        protected override void Seed(MyContext context)
        {
            var bill1 = new Bill { Name = "bill-1" };
            context.Bills.Add(bill1);

            for (int i = 0; i < 11; i++)
            {
                context.Transactions.Add(new Transaction
                {
                    AddDate = DateTime.Now.AddDays(-i),
                    Amount = 1000000000 + i,
                    Bill = bill1
                });
            }
            base.Seed(context);
        }
    }

    public static class Test
    {
        public static void RunTests()
        {
            Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyContext, Configuration>());
            using (var context = new MyContext())
            {
                var sum = context.Transactions.Sum(x => x.Amount);
                Console.WriteLine(sum);
            }
        }
    }

SELECT 
         [GroupBy1].[A1] AS [C1]
         FROM ( SELECT 
                    SUM([Extent1].[Amount]) AS [A1]
                    FROM [dbo].[Transactions] AS [Extent1]
                    )  AS [GroupBy1]

 Arithmetic overflow error converting expression to data type int.

var sum2 = context.Transactions.Sum(x => (Int64)x.Amount);

SELECT 
      [GroupBy1].[A1] AS [C1]
         FROM ( SELECT 
                    SUM( CAST( [Extent1].[Amount] AS bigint)) AS [A1]
                    FROM [dbo].[Transactions] AS [Extent1]
               )  AS [GroupBy1]                  

var date = DateTime.Now.AddDays(10);
var sum3 = context.Transactions
                  .Where(x => x.AddDate > date)  
                  .Sum(x => (Int64)x.Amount);               

SELECT 
     [GroupBy1].[A1] AS [C1]
        FROM ( SELECT 
                    SUM( CAST( [Extent1].[Amount] AS bigint)) AS [A1]
                    FROM [dbo].[Transactions] AS [Extent1]
                    WHERE [Extent1].[AddDate] > @p__linq__0
              )  AS [GroupBy1]

The cast to value type 'Int64' failed because the materialized value is null.
Either the result type's generic parameter or the query must use a nullable type.

var date = DateTime.Now.AddDays(10);
var sum3 = context.Transactions
                  .Where(x => x.AddDate > date)
                  .Sum(x => (Int64?)x.Amount) ?? 0;

 var sum4 = context.Bills.First().Transactions.Sum(x => (Int64?)x.Amount) ?? 0;

SELECT 
     [Extent1].[Id] AS [Id], 
     [Extent1].[AddDate] AS [AddDate], 
     [Extent1].[Amount] AS [Amount], 
     [Extent1].[BillId] AS [BillId]
   FROM [dbo].[Transactions] AS [Extent1]
   WHERE [Extent1].[BillId] = @EntityKeyValue1

var entry = context.Bills.First();
var sum5 = context.Entry(entry).Collection(x => x.Transactions).Query().Sum(x => (Int64?)x.Amount) ?? 0;

SELECT 
    [GroupBy1].[A1] AS [C1]
     FROM ( SELECT 
               SUM( CAST( [Extent1].[Amount] AS bigint)) AS [A1]
                   FROM [dbo].[Transactions] AS [Extent1]
                    WHERE [Extent1].[BillId] = @EntityKeyValue1
            )  AS [GroupBy1]                  

    <Grid>
        <Button Text="1" Grid.Row="0" Grid.Column="0" />
        <Button Text="2" Grid.Row="0" Grid.Column="1" />
        <Button Text="3" Grid.Row="1" Grid.Column="0" />
        <Button Text="4" Grid.Row="1" Grid.Column="1" />
    </Grid>

    <StackLayout Orientation="Vertical">
        <Entry Placeholder="User name" Text="{Binding UserName}" />
        <Entry IsPassword="True" Placeholder="Password" Text="{Binding Password}" />
        <Button Command="{Binding LoginCommand}" Text="Login" />
    </StackLayout>

public class LoginViewModel : BitViewModelBase
{
        public string UserName { get; set; }

        public string Password { get; set; }

        public BitDelegateCommand LoginCommand { get; set; }

        public LoginViewModel()
        {
            LoginCommand = new BitDelegateCommand(Login);
        }

        public async Task Login()
        {
            // Login implementation ...
        }
}

containerRegistry.RegisterForNav<LoginView, LoginViewModel>("Login");

await NavigationService.NavigateAsync("/Login", animated: false);

Bringing WebAssembly to the .NET Mainstream - Steve Sanderson, Microsoft

Many developers still consider WebAssembly to be a leading-edge, niche technology tied to low-level systems programming languages. However, C# and .NET (open-source, cross-platform technologies used by nearly one-third of all professional developers [1]) have run on WebAssembly since 2017. Blazor WebAssembly brought .NET into the browser on open standards, and is now one of the fastest-growing parts of .NET across enterprises, startups, and hobbyists. Next, with WASI we could let you run .NET in even more places, introducing cloud-native tools and techniques to a wider segment of the global developer community. This is a technical talk showing how we bring .NET to WebAssembly. Steve will demonstrate how it runs both interpreted and AOT-compiled, how an IDE debugger can attach, performance tradeoffs, and how a move from Emscripten to WASI SDK lets it run in Wasmtime/Wasmer or higher-level runtimes like wasmCloud. Secondly, you'll hear lessons learned from Blazor as an open-source project - challenges and misconceptions faced bringing WebAssembly beyond early adopters. [1] StackOverflow survey 2021 

how to <doing problem>   in <your programming language>

how to convert int to string in c#

<programming language> how <problem>

• 12 ساعت قبل
• دیروز
• لحظاتی پیش
• ...

public class RelativeTimeCalculator
{
    const int SECOND = 1;
    const int MINUTE = 60 * SECOND;
    const int HOUR = 60 * MINUTE;
    const int DAY = 24 * HOUR;
    const int MONTH = 30 * DAY;

    public static string Calculate(DateTime dateTime)
    {
        var ts = new TimeSpan(DateTime.Now.Ticks - dateTime.Ticks);
        double delta = Math.Abs(ts.TotalSeconds);
        if (delta < 1 * MINUTE)
        {
            return ts.Seconds == 1 ? "لحظه ای قبل" : ts.Seconds + " ثانیه قبل";
        }
        if (delta < 2 * MINUTE)
        {
            return "یک دقیقه قبل";
        }
        if (delta < 45 * MINUTE)
        {
            return ts.Minutes + " دقیقه قبل";
        }
        if (delta < 90 * MINUTE)
        {
            return "یک ساعت قبل";
        }
        if (delta < 24 * HOUR)
        {
            return ts.Hours + " ساعت قبل";
        }
        if (delta < 48 * HOUR)
        {
            return "دیروز";
        }
        if (delta < 30 * DAY)
        {
            return ts.Days + " روز قبل";
        }
        if (delta < 12 * MONTH)
        {
            int months = Convert.ToInt32(Math.Floor((double)ts.Days / 30));
            return months <= 1 ? "یک ماه قبل" : months + " ماه قبل";
        }
        int years = Convert.ToInt32(Math.Floor((double)ts.Days / 365));
        return years <= 1 ? "یک سال قبل" : years + " سال قبل";
    }

} 

var relativeTime=RelativeTimeCalculator.Calculate(DateTime.Now.AddMinutes(-10)); 

• معرفی ELMAH

• ELMAH 1.1

• یکپارچه کردن ELMAH با WCF RIA Services

...
}
catch (Exception ex)
{
   Elmah.ErrorSignal.FromCurrentContext().Raise(ex);
...