ASP.NET 4.5 introduces strongly typed data controls that are bound to models. This provides compile time checking and navigation support. Data controls now support model binding, which allows selecting, filtering, editing and validating data without needing to write additional code. Validation is supported through data annotations. Custom value providers and validation attributes can also be created to extend model binding functionality.

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