Expect everything to change...

Getting Data from Controller to View

1. ViewData - Assign a value with a key in the controller and read the value using the key in the View page

   public ActionResult Index()
   {
     ViewData["Message"] = "Hello, World";
     return View();
   }
   

2. ViewBag - allows an object to dynamically have properties added to it. So with a ViewBag, you can use the “.” notation.

   public ActionResult Index()
   {
     ViewBag.Message = "Hello, World";
     return View();
   }
   

3. TempData - is another dictionary for storing temporary data like the “ViewBag“ but is deleted at the end of the HTTP request

   //  marks the specified key in the dictionary for retention
   public void Keep(string key)
   // returns an object without marking the key for deletion
   public Object Peek(string key)
   

4. Strongly-Typed View Model Object – WebFormViewEngine

   <%@ Page Inherits="System.Web.Mvc.ViewPage" %>
    Product Name: <%: Model.Name %> 
   

5. Strongly-Typed View Model Object – Razor

   @model Mvc3App.Models.Product
    Product: @Model.Name 
   

Getting Data from View to Controller

1. Traditional Approach - HttpRequestBase
2. FormCollection Object
3. Action Parameters
4. Strongly type model binding to view

ActionResult() response types:

1. ViewResult - Renders a specified view to the response stream
2. PartialViewResult - Renders a specified partial view to the response stream
3. EmptyResult - An empty response is returned
4. RedirectResult - Performs an HTTP redirection to a specified URL
5. RedirectToRouteResult - Performs an HTTP redirection to a URL that is determined by the routing engine, based on given route data
6. JsonResult - Serializes a given object to JSON format
7. JavaScriptResult - Returns a piece of JavaScript code that can be executed on the client
8. ContentResult - Writes content to the response stream without requiring a view
9. FileContentResult - Returns a file to the client
10. FileStreamResult - Returns a file to the client, which is provided by a Stream
11. FilePathResult - Returns a file to the client

Primary Constructor

class Person(string name, int age)
{
    private string _name = name;
    private int _age = age;
 
    private string _address;
 
    public Person(string name, int age, string address) : this(name, age)
    {
         _address = address;
    }
 
    public void Speak()
    {
        Console.WriteLine("Hi, my name is {0} and I am {1} years old", _name, _age);
    }
}

Auto-properties

class Person(string name, int age)
{
    public string Name { get; set; } = name;
    public string Name1 { get; } = name;
}

Dictionary initializer

class Person(string name)
{
    private Dictionary _data = new Dictionary {["Name"] = name };

    Dictionary newWay = new Dictionary()
            {
                // Look at this!
                ["Afghanistan"] = "Kabul",
                ["Iran"] = "Tehran",
                ["India"] = "Delhi"
            };
}

class Person(string name, int age)
{
         
    public Dictionary Data { get; } = new Dictionary {["Name"] = name };
}

Declaration expressions

int age;
CalculateAgeBasedOn(1987, out age);

CalculateAgeBasedOn(1987, out var age);

Using await in a catch or finally block

public async Task DownloadAsync()
{
    try
    {}
    catch
    {
        await Task.Delay(2000);
    }
    finally
    {
        await Task.Delay(2000);
    }
}

Filtering Exceptions with Exception Filters

try
{
    throw new CustomException { Severity = 100 };
}
catch (CustomException ex) if (ex.Severity > 50)
{
    Console.WriteLine("*BING BING* WARNING *BING BING*");
}
catch (CustomException ex) // to catch all other exceptions
{
    Console.WriteLine("Whooops!");
}

Part 1

Part 2

Part 3

Part 4

Part 5

Part 6

Part 7

Part 8

Part 9

Challenge

var dbContext = new MyDBDataContext();
var userDetails = dbContext.Users.FirstOrDefault(userId => userId.UserId == id);
var user = new LearningMVC.Models.User();
if (userDetails != null)
{
    user.UserId = userDetails.UserId;
    user.FirstName = userDetails.FirstName;
    user.LastName = userDetails.LastName;
    user.Address = userDetails.Address;
    user.PhoneNo = userDetails.PhoneNo;
    user.EMail = userDetails.EMail;
    user.Company = userDetails.Company;
    user.Designation = userDetails.Designation;
}
return View(user);

Auto Mapper

Example

public ActionResult Index()
{
    var dbContext = new MyDBDataContext();
    var userList = from user in dbContext.Users select user;
    var users = new List();
    if (userList.Any())
    {
        foreach (var user in userList)
        {
            users.Add(new LearningMVC.Models.User()
                {
                    UserId = user.UserId, 
                    Address = user.Address, 
                    Company = user.Company, 
                    FirstName = user.FirstName,
                    LastName = user.LastName,
                    Designation = user.Designation,
                    EMail = user.EMail, 
                    PhoneNo = user.PhoneNo
                });
        }
    }
  
    return View(users);
}

Mapper.CreateMap();

LearningMVC.Models.User userModel = Mapper.Map(user);
users.Add(userModel);

public ActionResult Index()
{
    Mapper.CreateMap();
    var dbContext = new MyDBDataContext();
    var userList = from user in dbContext.Users select user;
    var users = new List();
    if (userList.Any())
    {
        foreach (var user in userList)
        {
            LearningMVC.Models.User userModel = 
              Mapper.Map(user);
            users.Add(userModel);
        }
    }
    return View(users);
}

Mapper.CreateMap().ForMember(emp => emp.Fullname,
map => map.MapFrom(p => p.FirstName + " " + p.LastName));

Using Traditional Approach

[HttpPost]
public ActionResult CalculateSimpleInterestResult()
{
    decimal principle = Convert.ToDecimal(Request["txtAmount"].ToString());
    decimal rate = Convert.ToDecimal(Request["txtRate"].ToString());
    int time = Convert.ToInt32(Request["txtYear"].ToString());

    decimal simpleInteresrt = (principle*time*rate)/100;

    StringBuilder sbInterest = new StringBuilder();
    sbInterest.Append("Interest : " + simpleInteresrt);
    return Content(sbInterest.ToString());
}

Using the FormCollection Object

[HttpPost]
public ActionResult CalculateSimpleInterestResult(FormCollection form)
{
    decimal principle = Convert.ToDecimal(form["txtAmount"].ToString());
    decimal rate = Convert.ToDecimal(form["txtRate"].ToString());
    int time = Convert.ToInt32(form["txtYear"].ToString());

    decimal simpleInteresrt = (principle*time*rate)/100;

    StringBuilder sbInterest = new StringBuilder();
    sbInterest.Append("Interest : " + simpleInteresrt);
    return Content(sbInterest.ToString());
}

Using the Parameters

[HttpPost]
public ActionResult CalculateSimpleInterestResult(string txtAmount, string txtRate, string txtYear)
{
    decimal principle = Convert.ToDecimal(txtAmount);
    decimal rate = Convert.ToDecimal(txtRate);
    int time = Convert.ToInt32(txtYear);

    decimal simpleInteresrt = (principle*time*rate)/100;

    StringBuilder sbInterest = new StringBuilder();
    sbInterest.Append("Interest : " + simpleInteresrt);
    return Content(sbInterest.ToString());
}

Strongly typed model binding to view

namespace CalculateSimpleInterest.Models
{
    public class SimpleInterestModel
    {
        public decimal Amount { get; set; }
        public decimal Rate { get; set; }
        public int Year { get; set; }
    }
}

[HttpPost]
public ActionResult CalculateSimpleInterestResult(SimpleInterestModel model)
{
    decimal simpleInteresrt = (model.Amount*model.Year*model.Rate)/100;

    StringBuilder sbInterest = new StringBuilder();
    sbInterest.Append("Interest : " + simpleInteresrt);
    return Content(sbInterest.ToString());
}