Do async and concurrent work with ActionBlock TPL DataFlow in c# 

public static void PrintNumbers()
{
    var numbers = new[] { 1,2,3,5,7,90 }; // from a data source
    foreach(var item in numbers)
    {
        Console.WriteLine(item);
    }    
}

public static void PrintNumbers(Func<int,string> formula)
{
    var numbers = new[] { 1,2,3,5,7,90 };  // from a data source
    foreach(var item in numbers)
    {
        var data = formula(item);
        Console.WriteLine(data);
    }    
}

 PrintNumbers(number => string.Format("{0:n0}",number));

 PrintNumbers((number) =>{ return string.Format("{0:n0}",number); });

using System;
using System.Web;
using System.Web.Caching;
using System.Collections.Generic;

namespace WebToolkit
{
    public static class CacheManager
    {
        public static void CacheInsert(this HttpContextBase httpContext, string key, object data, int durationMinutes)
        {
            if (data == null) return;
            httpContext.Cache.Add(
                key,
                data,
                null,
                DateTime.Now.AddMinutes(durationMinutes),
                TimeSpan.Zero,
                CacheItemPriority.AboveNormal,
                null);
        }
    }
}

var item = httpContext.Cache[key];
if (item == null)
{
    item = ReadDataFromDataSource();
    if (item == null)
          return null;

    CacheInsert(httpContext, key, item, durationMinutes);
}

using System;
using System.Web;
using System.Web.Caching;
using System.Collections.Generic;

namespace WebToolkit
{
    public static class CacheManager
    {
        public static void CacheInsert(this HttpContextBase httpContext, string key, object data, int durationMinutes)
        {
            if (data == null) return;
            httpContext.Cache.Add(
                key,
                data,
                null,
                DateTime.Now.AddMinutes(durationMinutes),
                TimeSpan.Zero,
                CacheItemPriority.AboveNormal,
                null);
        }

        public static T CacheRead<T>(this HttpContextBase httpContext, string key, int durationMinutes, Func<T> ifNullRetrievalMethod)
        {
            var item = httpContext.Cache[key];
            if (item == null)
            {
                item = ifNullRetrievalMethod();
                if (item == null)
                    return default(T);

                CacheInsert(httpContext, key, item, durationMinutes);
            }
            return (T)item;
        }
    }
}

var user = HttpContext.CacheRead(
                            "Key1",
                            15,
                            () => _usersService.FindUser(userId));

This article provides an introduction to a lightweight API for ASP.NET web services provided by DotNetify.SignalR NuGet package that can reduce a lot of boilerplate code when implementing real-time updates, and provide an example of how to create a real-time web component with VueJS without using Node.JS build. 

export interface Person {
  name: string;
  age: number;
}

export class LinqTestsComponent {

  people: Person[] = [
    { name: "User 4", age: 27 },
    { name: "User 5", age: 42 },
    { name: "User 6", age: 8 },
    { name: "User 1", age: 20 },
    { name: "User 2", age: 35 },
    { name: "User 3", age: 78 }
  ];

}

  logTitle(title: string) {
    console.log(`%c${title}`, "background: #222; color: #bada55");
  }

  logOriginalArray() {
    console.log(`original this.people:${JSON.stringify(this.people)}`);
  }

  logResult(message: string, result: any) {
    console.log(`${message}:${JSON.stringify(result)}`);
  }

  equivalentToWhere() {
    const youngerThan40 = this.people.filter(person => person.age < 40); // ECMAScript 5
    this.logResult("People younger than 40", youngerThan40);

    // Filtering on Multiple Criteria
    const youngsters = this.people.filter(
      person => person.age < 40 && person.name.toLocaleLowerCase().indexOf("user") !== -1);
    this.logResult("Users younger than 40", youngsters);
  }

People younger than 40:[
{"name":"User 4","age":27},
{"name":"User 6","age":8},
{"name":"User 1","age":20},
{"name":"User 2","age":35}
]

Users younger than 40:[
{"name":"User 4","age":27},
{"name":"User 6","age":8},
{"name":"User 1","age":20},
{"name":"User 2","age":35}
]

  equivalentToAny() {

    const anyUnder40 = this.people.some(person => person.age < 40); // ECMAScript 5
    this.logResult("Are any people under 40?", anyUnder40); // true

    // Filtering on Criteria Matching any Object Properties
    const filterBy = "user";
    const anyUsers = this.people.filter(person =>
      Object.keys(person).some(property => {
        let value = (<any>person)[property];
        if (typeof value === "string") {
          value = value.toLocaleLowerCase();
        }
        return value.toString().indexOf(filterBy) !== -1;
      })
    );
    this.logResult("anyUsers", anyUsers);
  }

Are any people under 40?:true
anyUsers:[
{"name":"User 4","age":27},
{"name":"User 5","age":42},
{"name":"User 6","age":8},
{"name":"User 1","age":20},
{"name":"User 2","age":35},
{"name":"User 3","age":78}
]

  equivalentToContains() {

    const searchElement: Person = { name: "User 4", age: 27 };
    const containsUser4 = this.people.includes(searchElement); // ECMAScript 2016 = ECMAScript 7
    this.logResult("Contains searchElement", containsUser4); // false -> only compares by reference and not by value.

    const indexOfUser4 = this.people.indexOf(searchElement); // ECMAScript 5
    this.logResult("indexOfUser4", indexOfUser4); // -1 -> only compares by reference and not by value.

    const stringifiedObj = JSON.stringify(searchElement);
    const includesUser4 = this.people.some(person => JSON.stringify(person) === stringifiedObj);
    this.logResult("includesUser4", includesUser4); // true -> compares by by value.
  }

  equivalentToAll() {
    const allUnder30 = this.people.every(person => person.age < 30); // ECMAScript 5
    this.logResult("Are all people under 30?", allUnder30); // false
  }

 Are all people under 30?:false

  equivalentToFirstOrDefault() {
    const vahidOrDefault = this.people.filter(item => item.name === "Vahid")[0] || null; // ECMAScript 5
    this.logResult("vahidOrDefault", vahidOrDefault);

    const user1OrDefault = this.people.find(item => item.name === "User 1") || null; // ECMAScript 2015 = ECMAScript 6
    this.logResult("user1OrDefault", user1OrDefault);
  }

  equivalentToFindIndex() {
    const index = this.people.findIndex(person => person.age === 8); // ECMAScript 2015 = ECMAScript 6
    this.logResult("index of the user with age 8", index)
  }

 index of the user with age 8:2

  equivalentToSelect() {
    const names = this.people.map(person => person.name); // ECMAScript 5
    this.logResult("Selected the names of people", names);
  }

  equivalentToAggregate() {
    // ECMAScript 5
    const aggregate = this.people.reduce((person1, person2) => {
      return { name: "", age: person1.age + person2.age };
    });
    this.logResult("Aggregate age", aggregate.age); // { age: 210 }
  }

 Aggregate age:210

  equivalentToForEach() {
    // ECMAScript 5
    this.people.forEach(person => {
      this.logResult("person", person);
    });
  }

 person:{"name":"User 4","age":27}
 person:{"name":"User 5","age":42}
 person:{"name":"User 6","age":8}
 person:{"name":"User 1","age":20}
 person:{"name":"User 2","age":35}
 person:{"name":"User 3","age":78}

    // ECMAScript 5
    let orderedByAgeAscending = this.people.sort((person1, person2) => {
      const a = person1.age;
      const b = person2.age;
      return a > b ? 1 : -1;
    });
    this.logResult("Ordered by age ascending", orderedByAgeAscending);

    orderedByAgeAscending = this.people.sort((person1, person2) => person1.age - person2.age);
    this.logResult("Ordered by age ascending", orderedByAgeAscending);

Ordered by age ascending:[
{"name":"User 6","age":8},
{"name":"User 1","age":20},
{"name":"User 4","age":27},
{"name":"User 2","age":35},
{"name":"User 5","age":42},
{"name":"User 3","age":78}
]

    const orderedByName = this.people.sort((person1, person2) => {
      // name1.localeCompare(name2) // is case insensitive
      // or use toUpperCase() to ignore character casing
      const name1 = person1.name.toUpperCase();
      const name2 = person2.name.toUpperCase();
      return name1 > name2 ? 1 : -1;
    })
    this.logResult("Ordered by name", orderedByName);
    this.logOriginalArray();

Ordered by name:[
{"name":"User 1","age":20},
{"name":"User 2","age":35},
{"name":"User 3","age":78},
{"name":"User 4","age":27},
{"name":"User 5","age":42},
{"name":"User 6","age":8}
]

original this.people:[
{"name":"User 1","age":20},
{"name":"User 2","age":35},
{"name":"User 3","age":78},
{"name":"User 4","age":27},
{"name":"User 5","age":42},
{"name":"User 6","age":8}
]

  chainFunctionCalls() {
    const namesOfPeopleOver30OrderedDesc =
      this.people
        .filter(person => person.age > 30)
        .map(person => person.name)
        .sort((name1, name2) => {
          // name1.localeCompare(name2) // is case insensitive
          // or use toUpperCase() to ignore character casing
          name1 = name1.toUpperCase();
          name2 = name2.toUpperCase();
          return name2 > name1 ? 1 : -1;
        });
    this.logResult("the names of all people over 30 ordered by name descending", namesOfPeopleOver30OrderedDesc);
  }

 the names of all people over 30 ordered by name descending:["User 5","User 3","User 2"]

skip2 -> the deleted elements:[
{"name":"User 3","age":78},
{"name":"User 4","age":27},
{"name":"User 5","age":42},
{"name":"User 6","age":8}
]

original this.people:[
{"name":"User 1","age":20},
{"name":"User 2","age":35}
]

When I tell my fellow computer scientists or software developers that I'm interested in philosophy of science, they first look a bit confused, then we have a really interesting discussion about it and then they ask me for some interesting books they could read about it. Given that Christmas is just around the corner and some of the readers might still be looking for a good present to get, I thought that now is the perfect time to turn my answer into a blog post! 

protobuf-net is a contract based serializer for .NET code, that happens to write data in the "protocol buffers" serialization format engineered by Google. The API, however, is very different to Google's, and follows typical .NET patterns (it is broadly comparable, in usage, to XmlSerializer, DataContractSerializer, etc). It should work for most .NET languages that write standard types and can use attributes. 

Nuget Package : https://www.nuget.org/packages/protobuf-net 

Microsoft.Jet.OLEDB.4.0 provider --> Excel 97-2003 format (.xls)
Microsoft.ACE.OLEDB.12.0 provider --> Excel 2007+ format (.xlsx)

PM> Install-Package ExcelDataReader
PM> Install-Package ExcelDataReader.DataSet

public ActionResult Upload()
{
      return View();
}

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Upload(HttpPostedFileBase upload)
{  
           // اعتبار سنجی فایل آپلود شده
            if (upload != null && upload.ContentLength > 0 && (upload.FileName.EndsWith(".xls") || upload.FileName.EndsWith(".xlsx")))
            {
                // با خواندن فایل به صورت باینری، این کتابخانه نیازی به نصب پیش نیازهای آفیس ندارد
                Stream stream = upload.InputStream;

                //  نیازی به نگرانی در مورد پسوند فایل نیست
                // کتابخانه به صورت خودکار کلاس مورد نظر برای پسوند مربوطه را استفاده می‌کند
                // ExcelDataReader.ExcelBinaryReader یا ExcelDataReader.ExcelOpenXmlReader
                IExcelDataReader reader = ExcelReaderFactory.CreateReader(stream);

                // روش ذکر شده در قسمت دوم برای خواندن کل اطلاعات بصورت یکجا
                DataSet result = reader.AsDataSet(new ExcelDataSetConfiguration()
               {
                    ConfigureDataTable = (tableReader) => new ExcelDataTableConfiguration()
                    {
                        // true: ردیف اول از فایل را به عنوان هدر در نظر می‌گیرد
                        // مقدار پیش فرض: false
                        UseHeaderRow = true
                    }
                });

                reader.Close();
                return View(result.Tables[0]);
            }
      ModelState.AddModelError("File", "Please upload Excel file ...");
      return View();
 }  

do {
        while (reader.Read()) {
       // reader.GetDouble(0);
        }
    } while (reader.NextResult());

@model System.Data.DataTable
@using System.Data;

<h2>Upload File</h2>

@using (Html.BeginForm("Upload", "Home", null, FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    @Html.AntiForgeryToken()
    @Html.ValidationSummary()

    <div>
        <input type="file" id="dataFile" name="upload" />
    </div>

    <div>
        <input type="submit" value="Upload" />
    </div>

    if (Model != null)
    {
        <table>
            <thead>
                <tr>
                    @foreach (DataColumn col in Model.Columns)
                    {
                        <th>@col.ColumnName</th>
                    }
                </tr>
            </thead>
            <tbody>
                @foreach (DataRow row in Model.Rows)
                {
                    <tr>
                        @foreach (DataColumn col in Model.Columns)
                        {
                            <td>@row[col.ColumnName]</td>
                        }
                    </tr>
                }
            </tbody>
        </table>
    }
}

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