Programming Windows Store Apps with C#

Chapter 7. Sharing

In this chapter, we’re going to look at one of the key tenets of the Windows Store app user experience: sharing.

One of the key problems with iPad is that information is stored in each app’s private silo. It’s hard to share information between apps, and really the only tool that you have is the copy-and-paste feature. With Window Store apps, information sharing between apps is front and center. Apps can register themselves as a share target, or they can share information by acting as a share source.

Those of you who have been around the block a few times will see similarities in this feature with Dynamic Data Exchange, or DDE. DDE was a feature introduced in very early versions of Windows that was designed to work in a very loose and decoupled way. The idea was that an application, say Excel, could tell Windows that it had some text information to share. You could then choose an application that understood text, such as Word. Windows would then marshal the data from one to the other using some extra magic atop the standard system clipboard.

Sharing in Windows Store apps works in pretty much that exact way. An app can indicate that it shares data, and you’ll receive a message asking for said data. You can provide a combination of text, HTML, URIs, bitmaps, files (storage items), and RTF data, or you can define custom formats. The OS will then find apps that are interested in receiving shared data (i.e., those that register as having a search contract) and present ...