Introduction to XAML and WPF

Introduction to WPF Next Generation for Desktop Applications Doncho Minkov Telerik School Academy schoolacademy.telerik.com Technical Trainer http://www.minkov.it

Table of Contents Windows Presentation Foundation (WPF)? WPF basic features WPF and other UI technologies Windows Forms DirectX Silverlight HTML + CS S WPF classes XAML basics

What is Windows Presentation Foundation?

What is Windows Presentation Foundation? Windows Presentation Foundation (WPF) An entirely new graphical display system for Windows Empowers rich-media applications Provides a clear separation between the UI (XAML) and the business logic (C#,VB.NET) Influenced by modern display technologies such as HTML , CSS and Flash Hardware-accelerated

V ector G raphics All WPF graphics are Direct3D applications Direct3D (part of DirectX) is used in graphical applications where performance is important Uses the video card hardware for rendering The result: high-quality rich-media UI Vector-based graphics allows to scale without loss of quality WPF implements a floating-point logical pixel system and supports 32-bit ARGB color

R ich T ext M odel WPF includes a number of extremely rich typographic and text rendering features Some of them were not available in GDI B uilding international fonts from composite fonts WPF text rendering takes advantage of ClearType technology Use caching of pre-rendered text in the video memory WPF has resolution-independent architecture

A nimation WFP supports time-based animations Presentation timers are initialized and managed by WPF Scene changes coordinated by using a storyboard Animations can be triggered By other external events Including user action Animation can be defined on a per-object basis directly from the XAML markup

A udio and V ideo S upport WPF can incorporate audio and video into a user interface Audio support in WPF is a thin layer over the existing functionality in Win32 and WMP WPF supports the video in formats WMV, MPEG and some AVI files Relationship between video and animation is also supported They are both ways of showing moving images Animation can be synchronized with media

S tyles and T emplates In WPF a style is a set of properties applied to content used for visual rendering Similar to the concept of CSS E.g. setting the font weight of a Button control Use them to standardize non-formatting characteristics WPF styles have specific features for building applications Ability to apply different visual effects based on user events

S tyles and T emplates (2) T emplates in WPF allow you to fully change the UI of anything in WPF K inds of t emplates available within WPF ControlTemplate ItemsPanelTemplate DataTemplate HierarchicalDataTemplate

C ommands Commands are more abstract and loosely-coupled version of events Examples: copy, cut, paste, save, etc. WPF support for commands reduces the amount of code we need to write It gives us more flexibility to change the UI without breaking the back-end logic Commands have action, source, target and binding

C ommands (2) The power of commands comes from the following three features WPF defines a number of built-in commands Commands have automatic support for input actions Some WPF controls have built-in behavior tied to various commands Commands are intended to do two things: Check whether an action is available Execute an action

D eclarative UI with XAML WPF introduces a new XML-based language for describing UI elements known as XAML XAML = eXtensible Application Markup Language XAML is a completely declarative language A declarative language says "what" An imperative language says "how" XAML describes the behavior and integration of components (in most cases UI components)

O bject- B ased D rawing At the lower-level WPF works in terms of shapes , not in terms of painting pixels Shapes are vector-based and can easily scale Developers create shape objects and let WPF maintain the display in the most optimized way WPF provides a number of ready-to-use shape objects like line, rectangle, ellipse, path, etc. Shape objects can be used inside panels and inside most WPF controls

WPF a nd O ther UI T echnologies

Windows Forms Windows Forms is the culmination of the display technology built on GDI+ and User32 It’s more mature than WPF Has solid limitations No separation between UI and the C# code WPF is the platform for the future of Windows development Based on DirectX and Direct3D Separation between the UI and C# code

DirectX WPF create multimedia applications with real-time graphics Such as complex physics-based simulators or cutting-edge action games WPF applications are DirectX applications As a result, even the most mundane business applications can use rich effects and antialiasing WPF graphics is entirely vector-based This allows zoom-in / soom-out with no loss of quality

Silverlight Silverlight is a cross-platform, cross-browser plugin, which contains WPF-based technology Rich Internet Application (RIA) platform Including XAML and subset of WPF Provides rich-media features such as video, vector graphics, and animations Silverlight and WPF share the XAML presentation layer Both technologies are similar, but Silverlight is limited in many aspects

HTML + CSS vs. XAML + Styles Cascading Style Sheets (CSS) is a stylesheet language Used to describe the presentation of information in HTML documents XAML elements have Style property Similar to CSS (as a concept) The HTML and XAML are tag based systems to describe UI XAML is more powerful in many aspects

XAML Basics XAML is an XML-based language for creating and initializing .NET objects It’s used in WPF as a human-authorable way of describing the UI Used to separate the UI from the C# code XAML contains a hierarchy of elements representing visual objects These objects are known as user interface elements or UI elements

Elements and Attributes UI elements have a set of common properties and functions Such as Width , Height , Cursor , and Tag properties Declaring an XML element in XAML Equivalent to instantiating the object via a parameterless constructor Setting an attribute on the object element Equivalent to setting a property of the same name

XAML Basics - Example Constructs button with caption "OK" <Window x:Class="MyFirstWpfApp.MainWindow" xmlns= "http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x= http://schemas.microsoft.com/winfx/2006/xaml Title="Hello, WPF" Height="300" Width="300"> <Button x:Name="button" Width="200" Height="25">OK</Button> </Window>

Example – E xplanation The root element, Window is used to declare a portion of a class The two XML namespace declarations pull in two commonly used namespaces The one for XAML itself The one for WPF Width , Height , Title are the XAML properties

What is XAML? e X tensible A pplication M arkup L anguage XAML is a declarative markup language Used to simplify creation of UI for a .NET apps Separates UI and Business logic XAML enables a workflow where different parties can work simultaneously The UI and the logic of an application can be developed using different tools (VS and Blend)

What is XAML? (2) XAML is an XML-based language for creating and initializing .NET objects It’s used in WPF and Silverlight as a human-authorable way of describing the UI Used to separate the UI from the C# code XAML contains a hierarchy of elements representing visual objects These objects are known as user interface elements or UI elements

D eclarative UI with XAML XAML introduces a new XML-based language for describing UI elements known as XAML XAML = eXtensible Application Markup Language XAML is a completely declarative language A declarative language says "what" An imperative language says "how" XAML describes the behavior and integration of components (in most cases UI components)

Property Elements Not all properties have just a string value Some must be set to an instance of an object XAML provide syntax for setting complex property values, called property elements Take the form TypeName.PropertyName contained inside an TypeName element <Ellipse> <Ellipse.RenderTransform> <RotateTransform Angle="45" CenterY="60" /> </Ellipse.RenderTransform> </Ellipse> A property element

Declarative vs. Programmatically? Why we need XAML?

Declarative vs. Programmatically In WPF/Silverlight each element can be done either declaratively or programmatically No difference in the execution and speed Instantiating element from the code behind ruins the idea of XAML The same as Windows Forms The following two examples are identical <Button Content="Click me!"/> Button button=new Button(); button.Content="Click me!"; With XAML From Code Behind

Declarative UI When not using XAML with WPF/Silverlight Miss the idea of separation of concerns Two parties cannot work simultaneously on the same file What happens when making object declaratively? It is the same as instantiating the element with parameterless constructor All the magic happens in InitializeComponents()

WPF vs. Windows Forms Windows Forms Framework to design applications with GUI Does the same job as WPF Everything is in one place Much like java's swings (by concept) Windows Presentation Foundation (WPF) Separate UI and Business Logic Why change the concept of the UI? In Windows Forms all the code is in one place Harder for front-end and back-end developers

Declarative or Programmatically? Live Demo

Introduction to XAML and WPF

More Related Content

What's hot

Viewers also liked

Similar to Introduction to XAML and WPF

More from Doncho Minkov

Recently uploaded

Introduction to XAML and WPF

Editor's Notes