ASP.NET 4.5 Web FormsNew features Brij Bhushan Mishra MVP-ASP.NET/IIS http://brijbhushan.net @brij_bhushan
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
Data controls in earlier versions Late bound Eval/Bind methods Does not provide navigational support Missing Compile time checking
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
Assign a property SelectMethod with the public method name written at code behind ◦ It should return IEnumerable or IQueryable object
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
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.
Create your own value provider by implementing IValueProvider interface ◦ GetValue method should return an object of type ValueProviderResult which should contain the value
Create your own custom attribute by Implementing ValueProviderSourceAttribute Override GetValueProvider which should return the instance of CustomValueProvider
Data controls provide the following Properties to support this feature ◦ InsertMethod ◦ UpdateMethod ◦ DeleteMethod
Model Binding supports Validation with the help of Data Annotations from System.ComponentModel.DataAnnotations namespace
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
ASP.NET introduced new Property ‘ShowModelStateErrors’ in ValidationSummary control. Display all the model validation errors
Can write your custom validation attribute by implement ValidationAttribute Override IsValid method write the validation logic in it.
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