Introduction
Dropdown list and Radio button are two very important controls for web. We frequently use it. In this article I will show you how to use dynamic dropdown list and radio button in CRUD operation.
Implementation Repository Pattern with ASP.NET MVC and Entity Framework
Let’s create a University Ranking application and implement Dropdown list and Radio button dynamically. Here I only show you CRUD operation on University Information page.
Tools and Technology used
I used following tools and technology to develop the project – Implementation of generic repository
Visual Studio 2013
Visual C#
ASP.NET MVC 5
Entity Framework 6
Razor view engine
Step 1: Create an ASP.NET MVC 5 application using Visual Studio 2013. I kept the application name “UniversityRanking”. Help: How to create first application using asp.net MVC Step 2: Configure connection string in web.config
Step 3: Create three models – “Country, Category and University”
Country
public class Country
{
public int Id { get; set; }
public string Name { get; set; }
}
Category
public class Category
{
public int Id { get; set; }
public string Name { get; set; }
}
[csharp]
University
[csharp]
public class University
{
public int Id { get; set; }
public string Name { get; set; }
[Required]
public int CountryId { get; set; }
[ForeignKey("CountryId")]
public virtual Country Country { get; set; }
[Required]
public int CategoryId { get; set; }
[ForeignKey("CategoryId")]
public virtual Category Category { get; set; }
}
Step 4: Create a DbContext name UniversityContext in Repository folder.
public class UniversityContext : DbContext
{
public UniversityContext()
: base("DefaultConnection")
{
}
public DbSet Universities { get; set; }
public DbSet Categories { get; set; }
public DbSet Countries { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
}
}
Step 5: Create a controller name – EmployeeController. Select template “MVC5 Controller with views, using entity framework”. EmployeeController will create in Controller folder and related views will be created in Views/Employee folder
Step 6: Now modify some of the action of UniversityController mentioned bellow (using comments).
public class UniversityController : Controller
{
private UniversityContext db = new UniversityContext();
// GET: /University/
public ActionResult Index()
{
var universities = db.Universities.Include(u => u.Category).Include(u => u.Country);
return View(universities.ToList());
}
// GET: /University/Details/5
public ActionResult Details(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
University university = db.Universities.Find(id);
if (university == null)
{
return HttpNotFound();
}
return View(university);
}
// Modify Create Action.
//GET: /University/Create
public ActionResult Create()
{
//ViewBag.CategoryId = new SelectList(db.Categories, "Id", "Name");
ViewBag.Categories = db.Categories.ToList();
ViewBag.CountryId = new SelectList(db.Countries, "Id", "Name");
return View();
}
// Modifed following action
// POST: /University/Create
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include="Id,Name,CountryId,CategoryId")] University university)
{
try
{
if (ModelState.IsValid)
{
db.Universities.Add(university);
db.SaveChanges();
return RedirectToAction("Index");
}
}
catch(Exception exp)
{
return RedirectToAction("Create");
}
//ViewBag.CategoryId = new SelectList(db.Categories, "Id", "Name", university.CategoryId);
//ViewBag.CountryId = new SelectList(db.Countries, "Id", "Name", university.CountryId);
ViewBag.Categories = db.Categories.ToList();
ViewBag.CountryId = new SelectList(db.Countries, "Id", "Name");
return View(university);
}
// Modifed following action
// GET: /University/Edit/5
public ActionResult Edit(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
University university = db.Universities.Find(id);
if (university == null)
{
return HttpNotFound();
}
//ViewBag.CategoryId = new SelectList(db.Categories, "Id", "Name", university.CategoryId);
ViewBag.Categories = db.Categories.ToList();
ViewBag.CountryId = new SelectList(db.Countries, "Id", "Name", university.CountryId);
return View(university);
}
// POST: /University/Edit/5
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit([Bind(Include="Id,Name,CountryId,CategoryId")] University university)
{
if (ModelState.IsValid)
{
db.Entry(university).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.CategoryId = new SelectList(db.Categories, "Id", "Name", university.CategoryId);
ViewBag.CountryId = new SelectList(db.Countries, "Id", "Name", university.CountryId);
return View(university);
}
// GET: /University/Delete/5
public ActionResult Delete(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
University university = db.Universities.Find(id);
if (university == null)
{
return HttpNotFound();
}
return View(university);
}
// POST: /University/Delete/5
[HttpPost, ActionName("Delete")]
[ValidateAntiForgeryToken]
public ActionResult DeleteConfirmed(int id)
{
University university = db.Universities.Find(id);
db.Universities.Remove(university);
db.SaveChanges();
return RedirectToAction("Index");
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
db.Dispose();
}
base.Dispose(disposing);
}
}
@Html.ActionLink("Edit", "Edit", new { id = item.Id }) |
@Html.ActionLink("Details", "Details", new { id = item.Id }) |
@Html.ActionLink("Delete", "Delete", new { id = item.Id })
}
Step 8: Add a link to _Layout page to access university information in Views/Shared
