Windows Presentation Foundation 4.5 Cookbook

Windows Presentation Foundation 4.5 Cookbook

By : Pavel Yosifovich

Buy this Book

Windows Presentation Foundation 4.5 Cookbook

By: Pavel Yosifovich

Buy this Book

Overview of this book

Windows Presentation Foundation (WPF) provides developers with a unified programming model for building rich Windows smart client user experiences that incorporate UI, media, and documents.WPF has become the leading technology for developing rich client applications on the Windows platform, packed with features and capabilities. However, WPF is big; in fact, it's huge, causing a steep learning curve for the beginner and even for those already using some WPF features.Windows Presentation Foundation 4.5 Cookbook provides clear recipes for common WPF tasks. It includes detailed explanations and code examples for customizing and enhancing the basic scenarios, while gaining a deep understanding of WPF mechanics and capabilities.WPF is different and requires a different mind-set and approach. This book provides recipes and insights not only in its design but also its practical implementation details.Starting from the foundations of WPF, such as dependency properties and XAML, the book touches on all major WPF aspects, such as controls and layout, resources, and digs deep into its unprecedented data binding capabilities.The book shows data and control templates in action, which allow full customizations of displayed data and controls in a declarative way. Supported by styles and resources makes data binding all the more powerful. The Model View View-Model pattern is presented as an effective way of maximizing decoupling of components, while providing an elegant way of expanding applications while maintaining a tight grip on complexity.The later parts discuss custom elements and controls ñ the ultimate customization mechanism, and looks at multithreading issues, and how .NET 4.5 task parallelism features can enhance application performance.

Windows Presentation Foundation 4.5 Cookbook

Credits

About the Author

About the Reviewers

www.PacktPub.com

Preface

Free Chapter

Foundations

Introduction

Creating custom type instances in XAML

Creating a dependency property

Using an attached property

Creating an attached property

Accessing a static property from XAML

Creating a custom markup extension

Handling routed events

Resources

Introduction

Using logical resources

Dynamically binding to a logical resource

Using user-selected colors and fonts

Using binary resources

Accessing binary resources in code

Accessing binary resources from another assembly

Managing logical resources

Layout and Panels

Introduction

Creating a table-like user interface

Dynamically sizing grid rows/columns

Creating a scrollable user interface

Creating a border around panels and elements

Placing elements in exact positions

Adding/removing elements to a panel dynamically

Creating a tabbed user interface

Implementing drag-and-drop

Using Standard Controls

Introduction

Working with text

Using content controls

Displaying images

Creating tooltips

Creating a list of items

Creating a standard menu

Creating a context menu

Selecting options with checkboxes and radio buttons

Manipulating tab order and focus

Application and Windows

Introduction

Creating a window

Creating a dialog box

Using the common dialog boxes

Creating ownership between windows

Creating a custom shaped window

Creating a single instance application

Handling an unhandled exception

Data Binding

Introduction

Element to element binding

Binding to a single object

Binding to a collection

Using data templates

Using value converters

Creating a master-detail view

Sorting and filtering bound collections

Grouping bound collections

Binding to multiple properties

Binding hierarchical data to a TreeView

Presenting data in a grid

Validating data

Commands and MVVM

Introduction

Using routed commands

Implementing a basic MVVM application

Building a simple MVVM framework

Building a complete MVVM style application

Creating an undo/redo system

Styles, Triggers, and Control Templates

Introduction

Creating and using styles

Applying a style automatically

Creating a property trigger

Using data triggers

Creating an event trigger

Creating a multi trigger

Using behaviors

Replacing the control template of a progress bar

Replacing the control template of a scroll bar

Customizing selection in a Selector control

Graphics and Animation

Introduction

Creating a custom shape

Applying transforms on elements

Manipulating a bitmap programmatically

Creating adorners

Creating property-based animations

Creating path-based animations

Creating custom animations

Adding animation easing to animations

Using custom effects with pixel shaders

Custom Elements

Introduction

Creating a user control

Handling standard commands in a user control

Creating a custom (templated) control

Customizing a default template of custom control

Creating a custom panel

Creating a lightweight custom element

Threading

Introduction

Updating the UI from a non-UI thread

Adding cancelation support

Using the BackgroundWorker component

Adding cancellation and progress with BackgroundWorker

Using a timer to do periodic updates

Using C# 5.0 to perform asynchronous operations

Index

Customer Reviews

5 star

4 star

3 star

2 star

1 star

Accessing a static property from XAML

XAML provides an easy way to set values of properties—type converters and the extended property syntax allow for flexible setting of values. However, some things cannot be expressed as a simple value, such as setting a property to the value of some static property.

Getting ready

Make sure Visual Studio is up and running.

How to do it...

We'll create an application that uses a static property from within XAML:

Create a new WPF Application named CH01.StaticProperties.
Open MainWindow.xaml. Replace the Grid element with a StackPanel.

Add some shapes as shown in the following code block:

    <StackPanel>
        <Ellipse Stroke="Black" Height="50" />
        <Rectangle Stroke="Black" Height="50" />
    </StackPanel>

Suppose we want to fill the ellipse with the desktop color selected by the user in Windows. WPF provides the SystemColors class, with many static properties that return a Brush representing the user's choice. For the desktop, this is a DesktopBrush property. We can try the following:
```
<Ellipse Stroke="Black" Height="50" 
Fill="SystemColors.DesktopBrush" />
```
This throws an exception at runtime, as it cannot be converted to any "known" color (such as Red or Blue). To access a static property, we must use the {x:Static} markup extension, as follows:
```
<Ellipse Stroke="Black" Height="50" 
Fill="{x:Static SystemColors.DesktopBrush}" />
```
This works. You can verify this by going to Control Panel, then selecting Personalization (on Windows 7 or 8).
Select Window Color (switch to the classic theme first if the following window is shown differently). The Window Color and Appearance dialog is displayed:
Change the desktop color and run the application again. You should see the ellipse filled with the new color.

Similarly, let's fill the rectangle with the active window caption color:

<Rectangle Stroke="Black" Height="50" 
Fill="{x:Static SystemColors.ActiveCaptionBrush}"/>

Running the application shows something like the following:
In this case, the active caption color on my system is a gradient, so the ActiveCaptionBrush provides the left side. The right side is provided by the GradientActiveCaptionBrush property. They are both brushes. If we wanted to recreate the caption gradient within the rectangle, we would need color objects, not brushes. Fortunately, these are provided via properties in the same class, named ActiveCaptionColor and GradientActiveCaptionColor. Let's combine these in a LinearGradientBrush:
```
<Rectangle Stroke="Black" Height="50">
   <Rectangle.Fill>
      <LinearGradientBrush EndPoint="1,0">
         <GradientStop Offset="0" 
Color="{x:Static SystemColors.ActiveCaptionColor}" />
         <GradientStop Offset="1" 
Color="{x:Static SystemColors.GradientActiveCaptionColor}" />
      </LinearGradientBrush>
   </Rectangle.Fill>
</Rectangle>
```
This is the final result:

How it works...

XAML basically has very few capabilities. It can create objects, set values for properties, and set up event handlers. This is intentional, as XAML is declarative in nature. It cannot, for instance, call methods. That would make it closer to an imperative language (such as C#), which would make its existence dubious at best.

Sometimes, however, declarative operations require more than setting up properties. A method may be involved, or some other unusual construct, but the intent may still be declarative. This is where markup extensions come in. They provide a way to extend XAML with new (hopefully declarative) capabilities.

A markup extension is a class that derives from System.Windows.Markup.MarkupExtension and implements a single method, ProvideValue. In this example we have used the {x:Static} markup extension, which allows accessing any static property (whether it belongs to WPF or not; if not, a XAML namespace mapping is required as explained in the recipe Creating custom type instances in XAML in this chapter). {x:Static} is implemented by the System.Windows.Markup.StaticExtension class. Note that if the markup extension class ends with "Extension" we can remove it when referring to it in XAML – the XAML compiler will search with and without the word "Extension". This means {x:Static} can be written {x:StaticExtension}. In fact, most markup extensions end with "Extension" (a notable exception is the Binding markup extension).

There's more...

There are other built in markup extensions. Here are some of the simplest:

{x:Null} specifies the null reference
{x:Type SomeType} is the equivalent to the typeof(SomeType) operator in C#

We'll look at other markup extensions in subsequent chapters.

Windows Presentation Foundation 4.5 Cookbook

By : Pavel Yosifovich

Windows Presentation Foundation 4.5 Cookbook

By: Pavel Yosifovich

Overview of this book

Related Content you might be interested in

Current Title:

Windows Presentation Foundation 4.5 Cookbook

Accessing a static property from XAML

Getting ready

How to do it...

How it works...

There's more...