Beginning ASP.NET 4.5 in CSharp and VB Opsylum

Data Controls x 455
to have unwanted HTML mixed with your own. You define the entire client markup through the
numerous templates the control exposes. However, this flexibility comes at a price: the control has
no built-in capabilities to page, sort, or modify data. You see more of the Repeater control in the
next chapter.
The ListView was introduced in ASP.NET 3.5 and is a best-of-all-worlds combination of the
GridView, the DataList, and the Repeater. It has undergone some changes in ASP.NET 4 and 4.5
that make it even easier to work with. The control supports editing, deleting, and paging of data,
similar to the GridView. It supports multi-column and multi-row layouts like the DataList offers,
and it enables you to completely control the markup generated by the control, just as the Repeater
does. It also supports inserting and updating data like the DetailsView or FormView controls. In
the next chapter, you see a lot more of the ListView control.
In ASP.NET 4, list controls were extended with a ClientIDRowSuffix property that enables you to
indicate the column whose value is used to create unique client-side IDs based on data in the database.
For this to work, you need to set the ClientIDMode property that you saw in earlier chapters
to Predictable.
In ASP.NET 4.5, the controls have been extended again with a new property: ItemType. You see
this property at work in the next chapter.
Single Item Controls
The DetailsView and FormView controls are
somewhat similar in that both of them can display
a single record at a time. The DetailsView
uses a built-in tabular format to display the data,
whereas the FormView uses templates to let you
define the look and feel of your data. A simple,
template-based DetailsView could look like the
one shown in Figure 13-3.
The FormView control and a few of the Login controls you’ll see in Chapter 16 have a
RenderOuterTable property. When you set this property to False (it defaults to True so you need
to set it explicitly) the control doesn’t generate a wrapping HTML element. This in turn
results in less code and cleaner HTML. Both controls enable you to define the templates for different
situations, such as a read-only display of data, and inserting and updating of data. You see how to
customize these templates in the second half of this chapter.
Paging Controls
FIGURE 13-3
Another useful control is the DataPager, which enables paging on other controls. For the time
being, you can only use it to extend the ListView control, but that might change with future versions
of the .NET Framework. The ListView and DataPager controls are discussed in Chapter 14.
For the data-bound controls to display something useful, you need to assign them a data source.
To bind this data source to the controls, two main methods are available: You can assign data to
the control’s DataSource property, or you can use one of the separate data source controls. In later
chapters, you see how to use the DataSource property; the different data source controls are the
topic of the following section.