Book Image

Windows Presentation Foundation 4.5 Cookbook

By : Pavel Yosifovich
Book Image

Windows Presentation Foundation 4.5 Cookbook

By: Pavel Yosifovich

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.
Table of Contents (18 chapters)
Windows Presentation Foundation 4.5 Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Using a timer to do periodic updates


It is sometimes useful to update parts of the user interface periodically. For example, an application may need to display the current time in some part of the UI. Or some color changes need to be made on a regular basis based on some runtime criteria. Although it's possible to create a thread that sleeps for a certain amount of time and then does the updates, this has two flaws: the first is that most of the time the thread sleeps. Threads are supposed to do useful work and not sleep most of the time – the very fact the thread exists requires it to have its stack space (1MB by default), which may be wasteful in such a case. The second flaw is that we would have to marshal the UI update call using some mechanism we've already seen (Dispatcher, SynchronizationContext, and so on), which makes the code cumbersome.

A timer can be used instead if such updates are required, without the need to create additional threads. In this recipe, we'll use the DispatcherTimer...