protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Add(new FunctionsConvention<MyContext>("dbo"));
    }

• نوع خروجی تابع باید از <IQueryable<T  باشد. T باید از جنسی باشد که معادل EDM آن موجود باشد. T می‌تواند از انواع اصلی (Primitive) باشد که در EF پشتیبانی می‌شوند (رجوع شود به  Entity Data Model: Primitive Data Types   )به طور مثال، int قابل استفاده است ولی uint خیر و یا می‌تواند از انواع غیر اصلی (  non-primitive ) باشند (enum/complex type/entity type ) که در مدل شما تعریف شده‌اند.
• پارامترهای متد باید از نوع اسکالر (primitive یا enum) باشند که قابل map شدن به نوع‌های EF باشند.
  
• نام متد،  DbFunction.FunctionName   و querystring ایی که به CreateQuery  پاس داده می‌شود باید همگی یکسان باشند.

 dotnet new react

spa.UseReactDevelopmentServer(npmScript: "start");

spa.UseProxyToSpaDevelopmentServer("http://localhost:3000");

> create-react-app clientapp

> cd clientapp
> npm install --save bootstrap axios react-toastify

import "bootstrap/dist/css/bootstrap.css";

import { ToastContainer } from "react-toastify";
import "react-toastify/dist/ReactToastify.css";

  render() {
    return (
      <React.Fragment>
        <ToastContainer />

import React, { useState } from "react";
import axios from "axios";
import { toast } from "react-toastify";

export default function UploadFileSimple() {

  const [description, setDescription] = useState("");
  const [selectedFile1, setSelectedFile1] = useState();
  const [selectedFile2, setSelectedFile2] = useState();


  return (
    <form>
      <fieldset className="form-group">
        <legend>Support Form</legend>

        <div className="form-group row">
          <label className="form-control-label" htmlFor="description">
            Description
          </label>
          <input
            type="text"
            className="form-control"
            name="description"
            onChange={event => setDescription(event.target.value)}
            value={description}
          />
        </div>

        <div className="form-group row">
          <label className="form-control-label" htmlFor="file1">
            File 1
          </label>
          <input
            type="file"
            className="form-control"
            name="file1"
            onChange={event => setSelectedFile1(event.target.files[0])}
          />
        </div>

        <div className="form-group row">
          <label className="form-control-label" htmlFor="file2">
            File 2
          </label>
          <input
            type="file"
            className="form-control"
            name="file2"
            onChange={event => setSelectedFile2(event.target.files[0])}
          />
        </div>

        <div className="form-group row">
          <button
            className="btn btn-primary"
            type="submit"
          >
            Submit
          </button>
        </div>
      </fieldset>
    </form>
  );
}

  const [description, setDescription] = useState("");
  const [selectedFile1, setSelectedFile1] = useState();
  const [selectedFile2, setSelectedFile2] = useState();

          <input
            type="text"
            className="form-control"
            name="description"
            onChange={event => setDescription(event.target.value)}
            value={description}
          />

          <input
            type="file"
            className="form-control"
            name="file1"
            onChange={event => setSelectedFile1(event.target.files[0])}
          />

<form enctype="multipart/form-data" action="/upload" method="post">
   <input id="file-input" type="file" />
</form>

let file = document.getElementById("file-input").files[0];
let formData = new FormData();
 
formData.append("file", file);
fetch('/upload/image', {method: "POST", body: formData});

  // ...

export default function UploadFileSimple() {
  // ...

  const handleSubmit = async event => {
    event.preventDefault();

    const formData = new FormData();
    formData.append("description", description);
    formData.append("file1", selectedFile1);
    formData.append("file2", selectedFile2);


      toast.success("Form has been submitted successfully!");

      setDescription("");
  };

  return (
    <form onSubmit={handleSubmit}>
    </form>
  );
}

  // ...

export default function UploadFileSimple() {
  const apiUrl = "https://localhost:5001/api/SimpleUpload/SaveTicket";

  // ...
  const [isUploading, setIsUploading] = useState(false);

  const handleSubmit = async event => {
    event.preventDefault();

    const formData = new FormData();
    formData.append("description", description);
    formData.append("file1", selectedFile1);
    formData.append("file2", selectedFile2);

    try {
      setIsUploading(true);

      const { data } = await axios.post(apiUrl, formData, {
        headers: {
          "Content-Type": "multipart/form-data"
        }}
      });

      toast.success("Form has been submitted successfully!");

      console.log("uploadResult", data);

      setIsUploading(false);
      setDescription("");
    } catch (error) {
      setIsUploading(false);
      toast.error(error);
    }
  };


  return (
  // ...
  );
}

<button
   disabled={ isUploading }
   className="btn btn-primary"
   type="submit"
>
  Submit
</button>

  const isFileValid = selectedFile => {
    if (!selectedFile) {
      // toast.error("Please select a file.");
      return false;
    }

    const allowedMimeTypes = [
      "image/png",
      "image/jpeg",
      "image/gif",
      "image/svg+xml"
    ];
    if (!allowedMimeTypes.includes(selectedFile.type)) {
      toast.error(`Invalid file type: ${selectedFile.type}`);
      return false;
    }

    const maxFileSize = 1024 * 500;
    const fileSize = selectedFile.size;
    if (fileSize > maxFileSize) {
      toast.error(
        `File size ${(fileSize / 1024).toFixed(
          2
        )} KB must be less than ${maxFileSize / 1024} KB`
      );
      return false;
    }

    return true;
  };

  const handleSubmit = async event => {
    event.preventDefault();

    if (!isFileValid(selectedFile1) || !isFileValid(selectedFile2)) {
      return;
    }

<button
            disabled={
              isUploading ||
              !isFileValid(selectedFile1) ||
              !isFileValid(selectedFile2)
            }
            className="btn btn-primary"
            type="submit"
>
   Submit
</button>

      const startTime = Date.now();

      const { data } = await axios.post(apiUrl, formData, {
        headers: {
          "Content-Type": "multipart/form-data"
        },
        onUploadProgress: progressEvent => {
          const { loaded, total } = progressEvent;

          const timeElapsed = Date.now() - startTime;
          const uploadSpeed = loaded / (timeElapsed / 1000);

          setUploadProgress({
            queueProgress: Math.round((loaded / total) * 100),
            uploadTimeRemaining: Math.ceil((total - loaded) / uploadSpeed),
            uploadTimeElapsed: Math.ceil(timeElapsed / 1000),
            uploadSpeed: (uploadSpeed / 1024).toFixed(2)
          });
        }
      });

  const [uploadProgress, setUploadProgress] = useState({
    queueProgress: 0,
    uploadTimeRemaining: 0,
    uploadTimeElapsed: 0,
    uploadSpeed: 0
  });

  const showUploadProgress = () => {
    const {
      queueProgress,
      uploadTimeRemaining,
      uploadTimeElapsed,
      uploadSpeed
    } = uploadProgress;

    if (queueProgress <= 0) {
      return <></>;
    }

    return (
      <table className="table">
        <thead>
          <tr>
            <th width="15%">Event</th>
            <th>Status</th>
          </tr>
        </thead>
        <tbody>
          <tr>
            <td>
              <strong>Elapsed time</strong>
            </td>
            <td>{uploadTimeElapsed} second(s)</td>
          </tr>
          <tr>
            <td>
              <strong>Remaining time</strong>
            </td>
            <td>{uploadTimeRemaining} second(s)</td>
          </tr>
          <tr>
            <td>
              <strong>Upload speed</strong>
            </td>
            <td>{uploadSpeed} KB/s</td>
          </tr>
          <tr>
            <td>
              <strong>Queue progress</strong>
            </td>
            <td>
              <div
                className="progress-bar progress-bar-info progress-bar-striped"
                role="progressbar"
                aria-valuemin="0"
                aria-valuemax="100"
                aria-valuenow={queueProgress}
                style={{ width: queueProgress + "%" }}
              >
                {queueProgress}%
              </div>
            </td>
          </tr>
        </tbody>
      </table>
    );
  };

{showUploadProgress()}

const formData = new FormData();
formData.append("description", description);
formData.append("file1", selectedFile1);
formData.append("file2", selectedFile2);

using Microsoft.AspNetCore.Http;

namespace UploadFilesSample.Models
{
    public class Ticket
    {
        public int Id { set; get; }

        public string Description { set; get; }

        public IFormFile File1 { set; get; }

        public IFormFile File2 { set; get; }
    }
}

using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using UploadFilesSample.Models;

namespace UploadFilesSample.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class SimpleUploadController : Controller
    {
        private readonly IWebHostEnvironment _environment;

        public SimpleUploadController(IWebHostEnvironment environment)
        {
            _environment = environment;
        }

        [HttpPost("[action]")]
        public async Task<IActionResult> SaveTicket([FromForm]Ticket ticket)
        {
            var file1Path = await saveFileAsync(ticket.File1);
            var file2Path = await saveFileAsync(ticket.File2);

            //TODO: save the ticket ... get id

            return Created("", new { id = 1001 });
        }

        private async Task<string> saveFileAsync(IFormFile file)
        {
            const string uploadsFolder = "uploads";
            var uploadsRootFolder = Path.Combine(_environment.WebRootPath, "uploads");
            if (!Directory.Exists(uploadsRootFolder))
            {
                Directory.CreateDirectory(uploadsRootFolder);
            }

            //TODO: Do security checks ...!

            if (file == null || file.Length == 0)
            {
                return string.Empty;
            }

            var filePath = Path.Combine(uploadsRootFolder, file.FileName);
            using (var fileStream = new FileStream(filePath, FileMode.Create))
            {
                await file.CopyToAsync(fileStream);
            }

            return $"/{uploadsFolder}/{file.Name}";
        }
    }
}

public async Task<IActionResult> SaveTicket([FromForm]Ticket ticket)

      const { data } = await axios.post(apiUrl, formData, {
        headers: {
          "Content-Type": "multipart/form-data"
        }}
      });

<body>
    <div class="container">
        <h2>Medical Questionnaire</h2>
        <form>
            <fieldset>
                <legend>Owner Info</legend>
                <div>
                    <label for="ownername">Owner name</label>
                    <input type="text" id="ownername" placeholder="Your Name">
                </div>
                <div>
                    <label for="owneremail">Email address</label>
                    <input type="email" id="owneremail" aria-describedby="emailHelp"
                        placeholder="Enter email">
                    <small id="emailHelp">We'll never share your email</small>
                </div>
            </fieldset>

            <fieldset>
                <legend>Pet Info</legend>
                <div>
                    <label for="petname">Pet name</label>
                    <input type="text" id="petname" placeholder="Your Pet's name">
                </div>
                <div>
                    <label for="pettype">Pet type</label>
                    <select id="pettype">
                        <option>Choose</option>
                        <option value="cat">Dog</option>
                        <option value="cat">Cat</option>
                        <option value="bird">Other</option>
                    </select>
                </div>
                <div>
                    <label for="reasonforvisit">Reason for today's visit</label>
                    <textarea id="reasonforvisit" rows="3"></textarea>
                </div>
                <div>
                    <label>Has your pet been spayed or neutered?</label>
                    <label><input type="radio" name="spayneut" value="yes"
                            checked> Yes</label>
                    <label><input type="radio" name="spayneut" value="no"> No</label>
                </div>
                <div>
                    <label>Has the pet had any of the following in the past 30
                        days</label>
                    <label><input type="checkbox"> Abdominal pain</label>
                    <label><input type="checkbox"> Lack of appetite</label>
                    <label><input type="checkbox"> Weakness</label>
                </div>
            </fieldset>
            <button type="submit">Submit</button>
        </form>

    </div><!-- content container -->
</body>

<div class="form-check">
    <label class="form-check-label">
        <input class="form-check-input" type="checkbox">
        Lack of appetite
    </label>
</div>

<div class="form-group">
    <label class="d-block">Has your pet been spayed or
        neutered?</label>
    <div class="form-check form-check-inline">
        <label class="form-check-label">
            <input class="form-check-input" type="radio" name="spayneut"
                   value="yes" checked>
            Yes
        </label>
    </div>
    <div class="form-check form-check-inline">
        <label class="form-check-label">
            <input class="form-check-input" type="radio" name="spayneut"
                   value="no"> No
        </label>
    </div>
</div>

<div class="form-group">
    <label for="owneremail" class="text-success">Email address</label>
    <input class="form-control is-valid" type="email" id="owneremail"
        aria-describedby="emailHelp" placeholder="Enter email">
    <small class="form-text text-muted" id="emailHelp">We'll
        never share your email</small>
    <div class="valid-feedback">
        Looks good!
    </div>
</div>

<body>
    <div class="container">
        <h2>Medical Questionnaire</h2>
        <form>
            <fieldset class="form-group">
                <legend>Owner Info</legend>
                <div class="form-group row">
                    <label class="form-control-label col-md-2 col-form-label text-md-right"
                        for="ownername">Owner</label>
                    <div class="col-md-10">
                        <input class="form-control" type="text" id="ownername"
                            placeholder="Your Name">
                    </div>
                </div>
                <div class="form-group row">
                    <label class="form-control-label col-md-2 col-form-label text-md-right"
                        for="owneremail">Address</label>
                    <div class="col-md-10">
                        <input class="form-control" type="text" id="owneremail"
                            placeholder="Address">
                    </div>
                </div>
                <div class="form-group row">
                    <div class="form-group col-6 offset-md-2">
                        <label class="form-control-label sr-only" for="ownercity">City</label>
                        <input class="form-control" type="text" id="ownercity"
                            placeholder="City">
                    </div>
                    <div class="form-group col-md-4 col-6">
                        <label class="form-control-label sr-only" for="ownerzip">Zip</label>
                        <input class="form-control" type="text" id="ownerzip"
                            placeholder="Zip">
                    </div>
                </div>

                <div class="form-group row">
                    <div class="offset-md-2 col-md-10">
                        <button class="btn btn-primary" type="submit">Submit</button>
                    </div>
                </div>
            </fieldset>
        </form>
    </div>
</body>

                <div class="form-group row">
                    <label class="form-control-label col-md-2 col-form-label text-md-right"
                        for="ownername">Owner</label>
                    <div class="col-md-10">
                        <input class="form-control" type="text" id="ownername"
                            placeholder="Your Name">
                    </div>
                </div>

<div class="form-group row">
   <div class="form-group col-6 offset-md-2">
   <label class="form-control-label sr-only" for="ownercity">City</label>
   <input class="form-control" type="text" id="ownercity"placeholder="City">
</div>

<div class="form-group row">
    <div class="offset-md-2 col-md-10">
        <button class="btn btn-primary" type="submit">Submit</button>
    </div>
</div>

<div class="form-group">
    <label class="form-control-label" for="donationamt">
        Donation Amount
    </label>
    <div class="input-group">
        <div class="input-group-prepend">
            <span class="input-group-text">$</span>
        </div>
        <input type="text" class="form-control" id="donationamt"
            placeholder="Amount">
        <div class="input-group-append">
            <span class="input-group-text">.00</span>
        </div>
    </div>
</div>

    <nav class="navbar bg-dark navbar-dark navbar-expand-sm">
        <div class="container">
            <div class="navbar-brand d-none d-sm-inline-block">
                Wisdom Pet Medicine
            </div>
            <div class="navbar-nav mr-auto">
                <a class="nav-item nav-link active" href="#">Home</a>
                <a class="nav-item nav-link" href="#">Mission</a>
                <a class="nav-item nav-link" href="#">Services</a>
                <a class="nav-item nav-link" href="#">Staff</a>
                <a class="nav-item nav-link" href="#">Testimonials</a>
            </div>
            <form class="form-inline d-none d-md-inline-block">
                <div class="input-group">
                    <label for="search" class="form-control-label sr-only"></label>
                    <input type="text" id="search" class="form-control"
                        placeholder="Search ...">
                    <div class="input-group-append">
                        <button class="btn btn-outline-light" type="submit">Go</button>
                    </div>
                </div>
            </form>
        </div>
    </nav>

namespace ConsoleApplicationTest
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("0172942284 => {0}", "0172942284".IsValidNationalCode());
            Console.WriteLine("1000000001 => {0}", "1000000001".IsValidNationalCode());
        }
    }

    public static class Helpers
    {
        public static Boolean IsValidNationalCode(this String nationalCode)
        {
            if (String.IsNullOrEmpty(nationalCode))
                throw new Exception("لطفا کد ملی را صحیح وارد نمایید");

            if (nationalCode.Length != 10)
                throw new Exception("طول کد ملی باید ده کاراکتر باشد");

            var regex = new Regex(@"[^0-9] ");
            if (!regex.IsMatch(nationalCode))
                throw new Exception("کد ملی تشکیل شده از ده رقم عددی می‌باشد؛ لطفا کد ملی را صحیح وارد نمایید");

            if (!Regex.IsMatch(nationalCode, @"^(?!(\d)\1{9})\d{10}$"))
                return false;

            var check = Convert.ToInt32(nationalCode.Substring(9, 1));
            var result = Enumerable.Range(0, 9)
                .Select(x => Convert.ToInt32(nationalCode.Substring(x, 1)) * (10 - x))
                .Sum() % 11;

            int remainder = result % 11;
            return check == (remainder < 2 ? remainder : 11 - remainder);

        }
    }
}

dbContext.Entry(entity).State = EntityState.Unchanged ;
dbContext.Entry(entity).State = EntityState.Added ; //or  Dbset.Add(entity)
dbContext.Entry(entity).State = EntityState.Modified ;
dbContext.Entry(entity).State = EntityState.Deleted ; // or  Dbset.Remove(entity)

 var CustomersWithGroup = dbContext.Customers.AsNoTracking().Include("Group").ToList();
 var CustomerFull = dbContext.Customers.AsNoTracking().Include("Group").Include("Bills").Include("Bills.BillDetails").ToList();

 public virtual void AddOrUpdate(T entity)
        {
            if (entity.Id == 0)
                Add(entity);
            else
                Update(entity);

        }

5) اگر بخواهیم موجودیت‌های رابطه ای در دیتا گرید ویو (ویندوز فرم) نشون بدیم باید چه کار کنیم؟

گرید ویو در ویندوز فرم قادر به نشون دادن فیلدهای رابطه ای نیست برای حل این مشکل می‌تونیم یک نوع ستون جدید برای گرید ویو تعریف کنیم و برای نشون دادن فیلدهای رابطه ای از این نوع ستون استفاده کنیم:

 public class DataGridViewChildRelationTextBoxCell : DataGridViewTextBoxCell
    {
        protected override object GetValue(int rowIndex)
        {
            try
            {
                var bs = (BindingSource)DataGridView.DataSource;
                var cl = (DataGridViewChildRelationTextBoxColumn)DataGridView.Columns[ColumnIndex];
                return getChildValue(bs.List[rowIndex], cl.DataPropertyName).ToString();
            }
            catch (Exception)
            {
                return "";
            }
        }

        private object getChildValue(object dataSource, string childMember)
        {
            int nextPoint = childMember.IndexOf('.');
            if (nextPoint == -1) return dataSource.GetType().GetProperty(childMember).GetValue(dataSource, null);
            string proName = childMember.Substring(0, nextPoint);
            object newDs = dataSource.GetType().GetProperty(proName).GetValue(dataSource, null);
            return getChildValue(newDs, childMember.Substring(nextPoint + 1));
        }
    }

    public class DataGridViewChildRelationTextBoxColumn : DataGridViewTextBoxColumn
    {
        public string DataMember { get; set; }

        public DataGridViewChildRelationTextBoxColumn()
        {
            CellTemplate = new DataGridViewChildRelationTextBoxCell();
        }
    }

نحوه استفاده را در ادامه می‌بینید. این روش توسط ویزارد گریدویو هم قابل استفاده است. موقع Add کردن Column نوع اون رو روی DataGridViewChildRelationTextBoxColumn   تنظیم کنید.

GroupNameColumn= new DataGridViewChildRelationTextBoxColumn(); //from your class
GroupNameColumn.HeaderText = "گروه مشتری";
GroupNameColumn.DataPropertyName = "Group.Name"; //EF  Property: Customer.Group.Name
GroupNameColumn.Visible = true;
GroupNameColumn.Width = 300;
DataGridView.Columns.Add(GroupNameColumn);

//dynamic reflection
PropertyInfo property = typeof (MyClass).GetProperty("Name");
MethodInfo method = typeof (MyClass).GetMethod("SomeMethod");

public string TextBoxFor<T>(Expression<Func<T,object>> expression);

<%= this.TextBoxFor(model => model.FirstName); %>

public PropertyInfo GetProperty<T>(Expression<Func<T, object>> expression)
{
 var memberExpression = expression.Body as MemberExpression;

 if (memberExpression == null)
     throw new InvalidOperationException("Not a member access.");

  return memberExpression.Member as PropertyInfo;
}

public class AddressMap : DomainMap<Address>
{
 public AddressMap()
 {
    Map(a => a.Address1);
 }
}

• Expression Tree Basics

• Functional Programming for Everyday .NET Development

• Introduction to static reflection

• The basics behind static reflection

• Dynamic reflection versus static reflection

• Static Reflection of property names

• Lisp is sin

int[] arr1 = { 1, 2, 10 };
int[] arr2 = { 1, 2, 5, 10 };
int[] arr3 = { 1, 2, 5, 6, 7, 8, 9, 10 };

int[] collection = { 1, 2, 3, 4 };

Console.WriteLine(collection is [1, 2, 3, 4]); // True
Console.WriteLine(collection is [1, 2, 4]); // False

Console.WriteLine(collection is [_, 2, _, 4]); // True
Console.WriteLine(collection is [.., 3, _]); // True

if (new[] { 6, 7, 8 } is [_, _, ..])
{
   Console.WriteLine($"collection with at least two items");
}

if (new[] { 0, 42, 42, 0 } is [0, .., 0])
{
   Console.WriteLine($"collection with first and last element equal to 0");
}

Console.WriteLine(collection is [_, >= 2, _, _]); // True

if (new[] { 9, -1, -2 } is [> 0, ..])
{
   Console.WriteLine($"collection with positive first element");
}

if (new[] { 1, 42, 0 } is [_, 42 or -42, ..])
{
   Console.WriteLine($"collection with second element equal to 42 or -42");
}

namespace CS11Tests;

public static class ListPatternsMatching
{
    public static void Test()
    {
        Console.WriteLine(CheckSwitch(new[] { 1, 2, 10 }));          // prints 1
        Console.WriteLine(CheckSwitch(new[] { 1, 2, 7, 3, 3, 10 })); // prints 1
        Console.WriteLine(CheckSwitch(new[] { 1, 2 }));              // prints 2
        Console.WriteLine(CheckSwitch(new[] { 1, 3 }));              // prints 3
        Console.WriteLine(CheckSwitch(new[] { 1, 3, 5 }));           // prints 4
        Console.WriteLine(CheckSwitch(new[] { 2, 5, 6, 7 }));        // prints 50
    }

    public static int CheckSwitch(int[] values)
        => values switch
        {
            [1, 2, .., 10] => 1,
            [1, 2] => 2,
            [1, _] => 3,
            [1, ..] => 4,
            [..] => 50
        };
}

if (new[] { 1, 2, 3 } is [var first, _, _])
{
   Console.WriteLine($"three item collection with first item {first}");
}

if (new[] { 4, 5, 6 } is [_, var second, _])
{
   Console.WriteLine($"three item collection with second item {second}");
}

var uri = new Uri("http://www.mysite.com/categories/category-a/sub-categories/sub-category-a.html");
var result = uri.Segments switch
{
    ["/"] => "Root",
    [_, var single] => single,
    [_, .. string[] entries, _] => string.Join(" > ", entries)
};

<label>
    Code:</label>
<textarea id="redactor_insert_code_area" name="redactor_insert_code_area" style="height: 211px; width: 538px;" />
<label>
    Language:</label>
<select id="redactor_insert_code_lang">
    <option>CSharp</option>
    <option>VB</option>
    <option>JScript</option>
    <option>Sql</option>
    <option>XML</option>
    <option>CSS</option>
    <option>Java</option>
    <option>Delphi</option>
</select>
<br />
<input type="button" name="insert" id="redactor_insert_btn" value="%RLANG.insert%" />

    code:
{
    title: 'Code',
    func: 'showCodesPage'
},

body .redactor_toolbar li a.redactor_btn_code span          { background: url(../img/code_red.png) no-repeat center; }