What is a simple explanation for displayfor and displaynamefor in asp.net?

Question

I have a class

public class Item {     public int ItemId { get; set; }      [Required(ErrorMessage = "Category is required")]     [Range(1, int.MaxValue, ErrorMessage = "Category is required")]     public int CategoryId { get; set; }      [Display(Name = "Current password")]     [Required(ErrorMessage = "Name is required")]     [StringLength(160)]     public string Name { get; set; }      [Required(ErrorMessage = "Price is required")]     [Range(0.01, 100.00,         ErrorMessage = "Price must be between 0.01 and 100.00")]     public decimal Price { get; set; }      public virtual Category Category { get; set; } } 

In my controller I pass an instance of this to view

public ActionResult Index()     {         var model = new Item         {             CategoryId = 1,             Name = "aaa",             Price = 2         };          return View("Index", model);                 } 

then in view I try to display name using

@model GenericShop.Models.Item  <p>                                 @Html.DisplayNameFor(m => m.Name)                                        </p> 

and get the following error

Compiler Error Message: CS1061: 'System.Web.Mvc.HtmlHelper' does not contain a definition for 'DisplayNameFor' and no extension method 'DisplayNameFor' accepting a first argument of type 'System.Web.Mvc.HtmlHelper' could be found (are you missing a using directive or an assembly reference?)

@Html.DisplayFor(m => m.Name) works fine, but I just cant see why

@Html.DisplayNameFor(m => m.Name) does not.

DisplayFor displays the value for the model item and DisplayNameFor simply displays the name of the property?

Answer 1

Almost there. :)

The DisplayNameFor shows the name of the property or the string defined in the display attribute for the property.

public class Item {     public int ItemId { get; set; }      [Display(Name = "Current name")]     [Required(ErrorMessage = "Name is required")]     [StringLength(160)]     public string Name { get; set; }      [Required(ErrorMessage = "Price is required")]     [Range(0.01, 100.00,         ErrorMessage = "Price must be between 0.01 and 100.00")]     public decimal Price { get; set; }  } 

Then @Html.DisplayNameFor(m => m.Name) would show 'Current name'.

@Html.DisplayNameFor(m => m.Price) would just show Price.

Note that you can also localize the display attribute like this:

[Display(ResourceType = typeof(MyResources), Name = "Name")] public string Name{ get; set; } 

Which in turn will look in the MyResources resc file. (If setup is done correctly).

The Html.DisplayFor shows the value of the field.