C# 4 and .NET 4

1178 ❘ ChaPTer 40 cOre Asp.net
(continued)
TemPlaTe aPPlies To desCriPTion
The easiest way to understand how to use these is through an example.
Using Templates
GridView, DetailsView,
FormView, ListView
GridView, DetailsView,
FormView
You will extend the table at the top of the Default.aspx page of PCSWebSite3 to contain a ListView
displaying each of the events stored in the database. You will make these events selectable such that details
of any event can be displayed by clicking on its name, in a FormView control.
First, you need to create new data sources for the data-bound controls. It is good practice (and strongly
recommended) to have a separate data source for each data-bound control.
The SqlDataSource control required for the ListView control, MRBEventData2, is similar to
MRBEventData, except that it needs to return only Name and ID data. The required code is as follows:
The data source for the FormView control, MRBEventDetailData, is more complicated, although you can
build it easily enough through the data source Configuration Wizard. This data source uses the selected item
of the ListView control, which you will call EventList, to get only the selected item data. This is achieved
using a parameter in the SQL query, as follows:
Used to display empty items — for
example, when no records are
available in a GridView
Used to format pagination
ListView Used to specify the output surrounding
groups of items
ListView Used between groups of items
ListView When using item groups, used to
supply output for empty items in a
group. This template is used when
there are not enough items in a
group to fill the group.
Here, the ID parameter results in a value being inserted in place of @ID in the select query. The
ControlParameter entry takes this value from the SelectedValue property of EventList, or uses –1 if
there is no selected item. At first glance, this syntax seems a little odd, but it is very flexible, and after you’ve
generated a few of these using the wizard, you won’t have any trouble assembling your own.
Next, you need to add the ListView and FormView controls. The changes to the code in Default.aspx in
the PCSWebSite3 project are shown in the following code:
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