Book Image

Microsoft Windows Azure Development Cookbook

By : Neil Mackenzie
Book Image

Microsoft Windows Azure Development Cookbook

By: Neil Mackenzie

Overview of this book

The Windows Azure platform is Microsoft's Platform-as-a-Service environment for hosting services and data in the cloud. It provides developers with on-demand computing, storage, and service connectivity capabilities that facilitate the hosting of highly scalable services in Windows Azure datacenters across the globe. This practical cookbook will show you advanced development techniques for building highly scalable cloud-based services using the Windows Azure platform. It contains over 80 practical, task-based, and immediately usable recipes covering a wide range of advanced development techniques for building highly scalable services to solve particular problems/scenarios when developing these services on the Windows Azure platform. Packed with reusable, real-world recipes, the book starts by explaining the various access control mechanisms used in the Windows Azure platform. Next you will see the advanced features of Windows Azure Blob storage, Windows Azure Table storage, and Windows Azure Queues. The book then dives deep into topics such as developing Windows Azure hosted services, using Windows Azure Diagnostics, managing hosted services with the Service Management API, using SQL Azure and the Windows Azure AppFabric Service Bus. You will see how to use several of the latest features such as VM roles, Windows Azure Connect, startup tasks, and the Windows Azure AppFabric Caching Service.
Table of Contents (16 chapters)
Microsoft Windows Azure Development Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Downloading a blob asynchronously


The Windows Azure Storage Client library provides synchronous and asynchronous versions of nearly all the methods that access the Windows Azure Storage Service.

The asynchronous methods follow the common language runtime (CLR) Asynchronous Programming Model (APM). In this model, asynchronous methods for an action are defined as a pair named BeginAction and EndAction. The asynchronous operation is initiated through a call to BeginAction and is cleaned up by a call to EndAction. BeginAction has a parameter that is a callback delegate and EndAction must be invoked in that delegate.

This apparent complexity can be greatly simplified through the use of a lambda expression to represent the callback delegate. Furthermore, local variables defined in the method containing the lambda expression are available inside the lambda expression. This removes any difficulty caused by a need to pass variables into the delegate. Using a lambda expression, instead of a callback...