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ASP.NET Working With Data-Bound Web Server Controls

Suppose we have:
List<Car> vCars = new List<Car>();

There are three types of databound controls: Simple databound controls(List, AdRotater), Composite data bound controls(GridView, DetailsView, FormView that inherit from CompositeDataBoundControl), and Hierarchal data bound controls (TreeView, Menu).

 



DataBoundControl has a DataBind method that can be used when data is ready. It calls DataBind for child controls as well. Page.DataBind() will call DataBind for all child controls.

Using DataSource Objects:
                                      BaseDataBound control exposes DataSource property that accepts objects that implement IEnumerable, IListSource, IDataSource, or IHierarchalDataSource. DataSourceID accepts ID of SqlDataSource. If both specified DataSourceID takes precedence.
GUI based data sources DataSourceControl or HierarchalDataSourceControl implement IDataSource and IListSource interface.
 

GUI Based Data Source
Description
AccessDataSource
MS Access (.mdb)
SqlDataSource
Open Database Connectivity(ODBC), Object Linking and Embedding Databases(OLEDB), SQL Server, SQL (.mdf)
XmlDataSource
XML file within your project. Use XPath for a subset, or XSL Transform can also be used.
ObjectDataSource
Any object implementing IEnumerable, IListSource, IDataSource, IHierarchalDatasource can be used. Like a collection, DataSet, DataTable can be used. 
SitemapDataSource
A valid sitemap file at root of the application.

Mapping Fields to Templates:
                                                Only controls that support templates. Templates have no default interface. Controls only provide binding support. Developer provides UI for templates. Templates can also contain ASP.NET Binding commands. Controls that support templates are GridView, DetailsView, and FormView.

Template
Description
HeaderTemplate
Optional. Header at the top of control.
FooterTemplate
Optional. Footer at the bottom of the control.
ItemTemplate
ItemTemplate is rendered for each row of the DataSource.
AlternatingItemTemplate
Optional. Just like ItemTemplate, But for each odd index.
SelectedItemTemplate
Optional. Template for Seleted Item Template.
SepratorTemplate
Optional. Template to seprate Item and alternate item.
EditItemTemplate
Optional. Edit mode template.



Using the DataBinder Class:
                                                DataBinder class provides a static method called Eval to access Data. Eval uses reflection, looks for the item in DataItem and retrieves the value.

<#% Eval(“VIN”) %>
An overload also provides format capabilities.
<#% Eval(“VIN”, “{0:C}”) %> //Currency

Eval provides read only access.
ASP.Net 2.0 provides Bind that allows updates as well.
<#% Bind(“VIN”) %>
<#% Bind(“VIN”, “{0:C}”) %>
GridView, DetailsView, and FormView only support Bind. The control must have a user-defines ID set, in order to user Bind.

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