C# 4 and .NET 4

1048 ❘ ChaPTer 36 business ApplicAtiOns with wpf
master details binding
Instead of just showing all the elements inside
a list, you might want or need to show detail
information about the selected item. It doesn’t
require a lot of work to do this. The Label and
TextBox controls are already defined; currently
they only show the first element in the list.
There’s one important change you have to make
to the ListBox. By default, the labels are bound
to just the first element of the list. By setting the
ListBox property IsSynchronizedWithCurren
tItem=“True”, the selection of the list box is set
to the current item. In Figure 36-7 you can see
the result; the selected item is shown in the detail
section labels:
multibinding
code snippet BooksDemo/BooksUC.xaml
Binding is one of the classes that can be used for data binding. BindingBase is the abstract base class of
all bindings and has different concrete implementations. Besides Binding, there’s also MultiBinding and
PriorityBinding. MultiBinding allows you to bind one WPF element to multiple sources. For example,
with a Person class that has LastName and FirstName properties, it is interesting to bind
both properties to a single WPF element:
public class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
}
figure 36-7
code snippet MultiBindingDemo/Person.cs
For MultiBinding, a markup extension is not available — thus the binding must be specified with XAML
element syntax. The child elements of MultiBinding are Binding elements that specify the binding to the
various properties. Here the FirstName and LastName properties are used. The data context is set with the
Grid element to reference the person1 resource.
To connect the properties together, MultiBinding uses a Converter to convert multiple values to one. This
converter uses a parameter that allows for different conversions based on the parameter:
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