C#’da Reflections’dan foydalanish

Tip nusxasini dinamik yaratishda, tipnig mavjud ob’yekt bilan aloqasini ta’minlashda, mavjud ob’yektning tipini aniqlashda va uning metodlarini ishlatishda(chaqirishda) yoki uning maydonlari va xususiyatlariga ruxsat 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.

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

Javob:

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;
        }
    }
}

2-Savol: Base Calss «bolalari»ni qanday aniqlash mumkin?

1-Javob:

Masalan, BaseClass nomi BasePerson bo’lsa:

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("");
                //ParameterInfo[] parameters = methodInfo.GetParameters();
                object[] parameters = new object[] { parametr1,parametr2,…,parametrN };
                var methodResult = methodInfo.Invoke(personObject, parameters);
                     …
            }

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

var logicList = new List();
                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
            {
                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.

Manba:

Mansur Kurtov