User1120430333 posted
An abstract class is a class that can't be instanced into an object. Another class can inherit from an abstract class and use the methods/behavior of an abstract class. An interface is a contract between the called/class object that the calling class/object
where the calling class object can use the public properties and/or methods of the called class/object that implements the interface that allows communications between two classes/objects..
An abstract example where all controllers in the MVC solution inherits from the Basecontroller that contains global exception handling in the Basecontroller. Any exception thrown in any code in a controller that inherits from the Basecontroller or code that
a controller is using in another object, the exception is handled by the Basecontroller.
The second thing that the Studentcontroller class/object is using an IStudentmodels interface for the Studentmodels class/object that was instanced by the Unity IoC container, which is being dependency injected into the Studentcontroller.
Usage of an interface promotes loose coupling..
https://www.c-sharpcorner.com/blogs/understanding-interfaces-via-loose-coupling-and-tight-coupling
https://www.c-sharpcorner.com/UploadFile/85ed7a/dependency-injection-in-C-Sharp/
https://www.tutorialsteacher.com/ioc
https://ardalis.com/new-is-glue
using System;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;
using log4net;
namespace MVC.Controllers
{
public abstract partial class BaseController : Controller
{
private ILog _logger;
protected BaseController()
{
_logger = LogManager.GetLogger(typeof(BaseController));
}
protected override void OnException(ExceptionContext filterContext)
{
AppException appException = new AppException(Convert.ToString(filterContext.Exception))
{
Type = filterContext.GetType().ToString(),
StackTrace = filterContext.Exception.StackTrace,
Source = filterContext.Exception.Source,
InnerException = Convert.ToString(filterContext.Exception.InnerException)
};
_logger.Error(appException.ToString());
Server.ClearError();
RedirectToControllers("Home", "Error");
}
private void RedirectToControllers(string control, string action)
{
var routeData = new RouteData();
routeData.Values["controller"] = control;
routeData.Values["action"] = action;
IController controller = new HomeController();
((IController) controller).Execute(new RequestContext(
new HttpContextWrapper(System.Web.HttpContext.Current), routeData));
}
}
}
using System.Web.Mvc;
using MVC.Models;
namespace MVC.Controllers
{
[Authorize]
public class StudentsController : BaseController
{
private IStudentModels studmods;
public StudentsController(IStudentModels studentModels)
{
studmods = studentModels;
}
// GET: Students
[AllowAnonymous]
public ActionResult Index()
{
return View(studmods.GetStudents());
}
//[AllowAnonymous]
public ActionResult Details(int id = 0)
{
return id == 0 ? null : View(studmods.GetStudentById(id));
}
public ActionResult Create()
{
return View(studmods.Create());
}
[HttpPost]
public ActionResult Create(StudentViewModels.Student student)
{
if (ModelState.IsValid)
{
studmods.Create(student);
return RedirectToAction("Index");
}
return View(student);
}
public ActionResult Edit(int id = 0)
{
return id == 0 ? null : View(studmods.Edit(id));
}
[HttpPost]
public ActionResult Edit(StudentViewModels.Student student)
{
if (ModelState.IsValid)
{
studmods.Edit(student);
return RedirectToAction("Index");
}
return View(student);
}
public ActionResult Delete(int id = 0 )
{
if (id > 0) studmods.Delete(id);
return RedirectToAction("Index");
}
}
}
using System.Collections.Generic;
namespace MVC.Models
{
public interface IStudentModels
{
StudentViewModels GetStudents();
StudentViewModels.Student GetStudentById(int id);
StudentViewModels.Student Create();
void Create(StudentViewModels.Student student);
StudentViewModels.Student Edit(int id);
void Edit(StudentViewModels.Student student);
void Delete(int id);
}
}
========================================================================================
using System.Collections.Generic;
using Entities;
using WebAPI.Controllers;
namespace MVC.Models
{
public class StudentModels : IStudentModels
{
private IStudentControllerAPI studapi;
public StudentModels(IStudentControllerAPI studentControllerApi)
{
studapi = studentControllerApi;
}
public StudentViewModels GetStudents()
{
var dtos = studapi.GetStudents();
var vm = new StudentViewModels {Students = new List<StudentViewModels.Student>()};
foreach (var dto in dtos)
{
var student = new StudentViewModels.Student
{
StudentID = dto.StudentID,
LastName = dto.LastName,
FirstName = dto.FirstName,
EnrollmentDate = dto.EnrollmentDate
};
vm.Students.Add(student);
}
return vm;
}
public StudentViewModels.Student GetStudentById(int id)
{
var dto = studapi.GetStudentById(id);
var student = new StudentViewModels.Student
{
StudentID = dto.StudentID,
FirstName = dto.FirstName,
LastName = dto.LastName,
EnrollmentDate = dto.EnrollmentDate,
EnrollsandCourses = new List<EnrollandCourseViewModel.EnrollandCourse>()
};
foreach (var dtoec in dto.EnrollsandCourses)
{
var ec = new EnrollandCourseViewModel.EnrollandCourse
{
Credits = dtoec.Credits,
Grade = dtoec.Grade,
Title = dtoec.Title
};
student.EnrollsandCourses.Add(ec);
}
return student;
}
public StudentViewModels.Student Create()
{
var student = new StudentViewModels.Student();
return student;
}
public void Create(StudentViewModels.Student student)
{
var dto = new DTOStudent
{
StudentID = student.StudentID,
FirstName = student.FirstName,
LastName = student.LastName,
EnrollmentDate = student.EnrollmentDate
};
studapi.CreateStudent(dto);
}
public StudentViewModels.Student Edit(int id)
{
var dto = studapi.GetStudentById(id);
var student = new StudentViewModels.Student
{
StudentID = dto.StudentID,
FirstName = dto.FirstName,
LastName = dto.LastName,
EnrollmentDate = dto.EnrollmentDate
};
return student;
}
public void Edit(StudentViewModels.Student student)
{
var dto = new DTOStudent
{
StudentID = student.StudentID,
FirstName = student.FirstName,
LastName = student.LastName,
EnrollmentDate = student.EnrollmentDate
};
studapi.UpdateStudent(dto);
}
public void Delete(int id)
{
studapi.DeleteStudent(id);
}
}
}
