Reflections in CSharp

Using Reflections in C#

       Tip ekzemplyarini dnamik yaratishda, tipnig mavjud ob’yekt bilan aloqasini ta’minlashda, mavjud ob’yektning tipini aniqlashda va uning metodlarini ishlatishda(chaqirishda) yoki uning maydonlari va xususiyatlariga dostup olishda Reflectiondan foydalaniladi.

Masalan,

string myStringValue=”Learning reflections in C#”;

System.Type type= myStringValue.GetType();

System.Console.WriteLine(type);

Natija: Sytem.String

Ushbu misolda GetType orqali reflection ishlatildi va ob’yektning tipi aniqlandi

     Reflection – shunday jarayonki unda dastur vaziyatga qarab o’z struktura va ko’rinishini o’zgartirishi mumkin.

Question 1: Dastur ishlayotgan vaqtda biror string tipidagi o’zgaruvchining faqat nominigina bilgan holda uning qiymatini qanday o’zgartirish mumkin?

Answer:

class Program

    {

        private static string a="test1", b="test2", c="test3";

        private static string s = "test string";

        static void Main(string[] args)

        {

            Console.WriteLine("O'zgaruvchi nomini kiriting:");

            string varName = Console.ReadLine();

            Console.WriteLine("O'zgaruvchi yangi qiymatini kiriting:");

            string newValue = Console.ReadLine();

            Type t = typeof(Program);

            FieldInfo fieldInfo=t.GetField(varName,BindingFlags.NonPublic|BindingFlags.Static);

            if (fieldInfo != null)

            {

                string varInfo1 = string.Format("{0} o'zgaruvchining joriy qimati:{1}",fieldInfo.Name,fieldInfo.GetValue(null));

                Console.WriteLine(varInfo1);

                fieldInfo.SetValue(null,newValue);

                string varInfo2 = string.Format("{0} o'zgaruvchining yangi qimati:{1}", fieldInfo.Name, fieldInfo.GetValue(null));

                Console.WriteLine(varInfo2);

            }

            else Console.WriteLine("Bunday o'zgaruvchi aniqlanmagan!");

           

            Console.ReadLine();

        }

    }

Joriy koddagi assembly(project, ya'ni assemblyni build qilganda .exe yoki .dll fayl ko'rinishga o'tadi) tiplarni(projectdagi classlar, interfacelar,…) aniqlash

Projectda quyidagilar aniqlangan bo’lsin:

namespace xyz.Test1.fullinfo

{

    public class ClassTest

    {

       //…

    }

}

namespace ReflactionTest

{

    abstract class AbstractClassTest

    {

       //…

    }

}

namespace ReflactionTest

{

    interface Interface1

    {

       //…

    }

}

Barcha assembly tiplar ro’yxatini quyidagi kod yordamida aniqlash mumkin:

namespace ReflactionTest

{

    class Program

    {

        static void Main(string[] args)

        {

            Assembly assembly = Assembly.GetExecutingAssembly();

            Type[] assemblyTypes = assembly.GetTypes();

            foreach (Type t in assemblyTypes)

                Console.WriteLine(t.Name);

            Console.ReadLine();

        }

    }

}

Natija:

ClassTest

ArstractClassTest

Interface1

Sinf nomi orqali undagi metodni Reflection yordamida ishlatish:

using System;

using System.Collections.Generic;

using System.Text;

using System.Reflection;

namespace ReflectionTest

{

    class Program

    {

        static void Main(string[] args)

        {

            Type testType = typeof(TestClass);

            ConstructorInfo ctor = testType.GetConstructor(System.Type.EmptyTypes);

            if(ctor != null)

            {

                object instance = ctor.Invoke(null);

                MethodInfo methodInfo = testType.GetMethod("TestMethod");

                Console.WriteLine(methodInfo.Invoke(instance, new object[] { 20 }));

            }

            Console.ReadKey();

        }

    }

    public class TestClass

    {

        private int testValue = 35;

        public int TestMethod(int numberToAdd)

        {

            return this.testValue + numberToAdd;

        }

    }

}

Question 2: Base Calss “bolalari”ni qanday aniqlash mumkin?

Answer 1:

Masalan, BaseClass nomi BasePerson b.sa:

 var result = AppDomain.CurrentDomain.GetAssemblies()

                       .SelectMany(assembly => assembly.GetTypes())

                       .Where(type => type.IsSubclassOf(typeof(BasePerson)));

            foreach (Type item in result)

            {

                var personObject = Activator.CreateInstance(item);

                MethodInfo methodInfo = item.GetMethod("<Person sinfidagi metod nomi>");

                //ParameterInfo[] parameters = methodInfo.GetParameters();

                object[] parameters = new object[] { parametr1,parametr2,…,parametrN };

                var methodResult = methodInfo.Invoke(personObject, parameters);

                     …

            }

Answer 2:

BaseLogic sinfi abstract shaklda aniqlangan va u check(column1,column2) metodiga ega, undan inherities olgan barcha sinflardning check metodi natijalarini olish:

` var logicList = new List<BaseLogic>();

                var types = Assembly.GetExecutingAssembly().GetTypes();

                foreach (var type in types)

                {

                    if (type.IsSubclassOf(typeof(BaseLogic)))

                    {

                        logicList.Add((BaseLogic)Activator.CreateInstance(type));

                    }

                }

Ishlatishda:

logicList.Where(w=>w.Weight<=weight).ToList().ForEach(logic=>

            {

                primeryKeyColumn.Parent = _tables.Find(f => f.ID == primeryKeyColumn.ParentID);

                forignKeyColumn.Parent = _tables.Find(f => f.ID == forignKeyColumn.ParentID);

                var relationship = logic.Check(primeryKeyColumn,forignKeyColumn);

}

Kabi bo’ladi

Used LINKS:

http://oreilly.com/catalog/progcsharp/chapter/ch18.html

http://csharp.net-tutorials.com/reflection/introduction/

http://msdn.microsoft.com/en-us/library/ms173183.aspx

http://www.csharp-examples.net/reflection-examples/

http://www.tutorialspoint.com/csharp/csharp_reflection.htm