Introduction XAML WPF
PV178: Programming for .NET Framework
Windows Presentation Foundation
Vojtˇech Forejt, forejt@fi.muni.cz
Martin Osovsk´y, osovsky@ics.muni.cz
Faculty of Informatics and Institute of Computer Science
Masaryk University
April 16, 2009
Introduction XAML WPF
Drawbacks of Most GUI Libraries
UI design and application logic are not separated
Do not take advantage of current technologies
Aimed at one particular area (web, client GUI, 2D or 3D
graphics)
Introduction XAML WPF
WPF Overview
Framework for working with graphics
user interface, 2D and 3D
Separation of UI design and application logic
Goes beyond WinForms, but does not supersede it
Windows.Forms.* namespaces
From .NET Framework 3.0, pre-alpha in Mono
Introduction XAML WPF
Example
ColorPicker3D
Introduction XAML WPF
WPF Assemblies and Namespaces
WindowsBase.dll
PresentationCore.dll
PresentationFoundation.dll
System.Windows
System.Windows.Controls
System.Windows.Markup
System.Windows.Media
System.Windows.Navigation
System.Windows.Shapes
Introduction XAML WPF
XAML
stands for eXtensible Application Markup Language
Declarative markup language
Allows to create UI using XML syntax
Objects – tags; Properties – tags or attributes
or
Objects are instantiated automatically
Introduction XAML WPF
Example
SimpleWpfExample
Introduction XAML WPF
XAML cont.
XAML file “defines” a partial class specified by Class
attribute of root element
Root element determines the base class
Application logic is placed in separate file with a partial class,
written e.g. in C#
Introduction XAML WPF
XAML – How Does It Work
XAML is compiled to BAML (Binary Application Markup
Language)
BAML is stored in assembly as a resource
When the application starts, BAML is read and appropriate
objects are created
Introduction XAML WPF
Visual Tree
Contains elements that are rendered on the screen
(Rougly) corresponds to the tree in XAML file
Introduction XAML WPF
Layouts
WrapPanel – elements positioned from left to right (or from
topto bottom, depending on Orientation), wraped at the
end of line
DockPanel – child elements positioned to the edges of the
panel
Grid – table-like positioning
Canvas – absolute positioning
StackPanel – Positions element in line (horosintally or
vertically, depending on Orientation)
Introduction XAML WPF
Example
WpfLayoutsExample
Introduction XAML WPF
Controls
Well-known controls are available
TextBox, Button, ListBox, TabControl, ListView,
CheckBox, RadioButton,. . .
Several new controls
Expander
PasswordBox
Introduction XAML WPF
Controls cont.
Controls contain
Methods
Properties
Events – routed events, extension of ordinary CLR events
Commands – Cut, Paste,...
Application logic in C# (or another language)
Data binding
Templates
Introduction XAML WPF
Routed Events
Extend CLR events
Invoke handlers on multiple elements of visual tree (“routed”
through a tree)
Routing strategies
Bubbling – event handlers are invoked from the source to the
root
Direct – only handler on the source is invoked
Tunelling – event handlers are invoked from the tree to the
source
Typically, is bubbling and is preceded by tunelling
Preview
Setting Handled property to true prevents invoking all
following handlers
Introduction XAML WPF
Example
RoutedEventsExample
Introduction XAML WPF
Commands
Counterpart of Actions in Java
Represent high-level tasks (Cut, Copy, Paste...) that can be
executed by or on different objects.
Extend RoutedCommand class
Methods CanExecute and Execute
Command source – control executing the command
Command target – control on which the command is
executed
CommandBinding class – associates a command with event
handlers
events CanExecute and Execute
Introduction XAML WPF
Example
WpfCommandExample
Introduction XAML WPF
Data Binding
Connects UI with application logic
Synchronization between data and its visual representation
Binding target – (almost) any property of a control
Binding source – property of a control, ADO.NET, XML,
collection
Introduction XAML WPF
Example
WpfDataBindingExample
Introduction XAML WPF
Example
ColorPicker3D