Describes latest changes on asp.net 4.5.

1. ASP.NET 4.5 Web Forms
New features
Brij Bhushan Mishra
MVP-ASP.NET/IIS
http://brijbhushan.net
@brij_bhushan

2.  Earlier Version’s Data Control
 Strongly typed data controls
 Model Binding
◦ Selecting data
◦ Filtering Data
◦ Custom value Provider
◦ Editing Data
◦ Validations
◦ Custom validation
 Support for HTML Encoding

3.  Data controls in earlier versions
 Late bound Eval/Bind methods
 Does not provide navigational support
 Missing Compile time checking

4.  ASP.NET 4.5 introduces ItemType property with
Data controls
◦ Now define the type of model to your data controls
◦ Item will be strongly coupled with model
◦ Provides intellisence support, compile time checking and
navigational support as well
◦ There are two new typed variable introduced that is used
in Data-binding expressions Item and BindItem.
◦ Item is used in one-way data-binding expressions while
BindItem is used two way binding

5.  One way binding –
 Two way Binding

6.  Assign a property SelectMethod with the public
method name written at code behind
◦ It should return IEnumerable or IQueryable object

7.  Automatically binds the data to the control
 No need to assign the DataSource property and
no need to call DataBind method
 Automatically supports Paging and sorting
◦ Handled by the SQL server with the help underlying LINQ
provider

8.  Can have filtering parameters in Select Method
 Parameters fetch value from the given Value
providers. Some value providers are
◦ Query string
◦ Session
◦ Cookies
◦ Controls
◦ Form Values etc
We can write custom Value Providers as well.

9.  Create your own value provider by implementing
IValueProvider interface
◦ GetValue method should return an object of type
ValueProviderResult which should contain the value

10.  Create your own custom attribute by
Implementing ValueProviderSourceAttribute
 Override GetValueProvider which should return
the instance of CustomValueProvider

11.  Data controls provide the following Properties to
support this feature
◦ InsertMethod
◦ UpdateMethod
◦ DeleteMethod

12.  Model Binding supports Validation with the help
of Data Annotations from
System.ComponentModel.DataAnnotations
namespace

13.  If your control is model bound on the Type these
validation rules are fired
 Page object has a new ModelState property
◦ ModelState.IsValid returns true if there is no validation
errors
◦ Provide list of all errors

14.  ASP.NET introduced new Property
‘ShowModelStateErrors’ in ValidationSummary
control.
 Display all the model validation errors

15.  Can write your custom validation attribute by
implement ValidationAttribute
 Override IsValid method write the validation logic
in it.

16.  ASP.NET 4.5 provides support to encode the
data in data binding expressions.
 Add a colon (:) to the end of the <%# prefix
that marks the data-binding expression