Making the Most Out of Charms and Contracts

Abstract

Contracts and charms are two new concepts introduced in Windows 8 that not only revolutionize the activity of app-to-app communication, but also introduce new usage scenarios for developers to work with. Using charms, the user can search across the entire device as well as in applications, send content to other applications or devices, and access settings in a standardized manner. Interoperability between applications can be further enhanced with the use of contracts. The beauty of this approach is that each application installed on a Windows 8 system enhances the system capabilities through well-defined extensions to formal interactions such as opening a file or choosing a contact from the contact store. As a Windows 8 app developer, you use contracts as a mechanism to handle a user’s interaction through charms; you also use contracts to facilitate this implicit interaction between applications. This chapter talks more about contracts later. Let’s get started.