Chapter 16: The Explorer Shell - Programming Microsoft Windows Ce Net 3Rd [Electronic resources] نسخه متنی

Chapter 16: The Explorer Shell

Overview

One of the unique aspects of Windows CE is that different Windows CE platforms have different shells. The default shell for the embedded versions of Windows CE is derived from the old Handheld PC shell. The look and feel of the Explorer shell is significantly different from the shell for the Pocket PC. Despite differences, the parts of the shells that are the same (and there are plenty of common shell components) share the underlying API.

The Explorer shell is derived from the Windows 95 and 98 shells. To the user, the look is almost pure Windows 95. That is, of course, by design. The folks at Microsoft figured that having the Windows CE shell resemble the Windows 95 shell would flatten the user's learning curve and enhance the acceptability of Windows CE devices.

On the surface, the shell used by the Pocket PC has nothing in common with the Windows 95 shell. Gone are both the Explorer and the familiar desktop icons. In place of the Explorer is the Today screen, which displays data from applications directly on the desktop. But while the Explorer is gone, some of the underlying plumbing remains. Both systems have a Start button. The Start button on the Pocket PC is located in the upper left corner of the Pocket PC screen. Both systems also use special directories and the shell namespace, which I'll talk about shortly.

Although the Explorer shell resembles the Windows 95 shell, it's not as flexible. Most of the powerful interfaces available under Windows 95, such as the ability to drag and drop objects between programs, are either only partially implemented or not implemented at all. The goal of the programmers of the Explorer shell seemed to be to implement as few of the native COM interfaces as possible while still retaining the ability to contain the Internet viewing capabilities of an embedded Internet Explorer in the shell. That said, the Explorer shell does use some COM interfaces. In fact, the newest version of the Explorer shell has exposed the COM interfaces to support desktop style name space extensions that allow the Explorer to navigate into virtual folders that are exposed via COM interfaces.

Starting with Windows CE .NET 4.2, the operating system now exposes most of the Pocket PC shell APIs such as SHInitDialog and the like that assist Pocket PC applications in providing the Pocket PC look and feel. The implementation of some of these functions is up to the OEM that implements them, but at least it is now possible for a non–Pocket PC system to run many of not most Pocket PC applications. This chapter covers the concept of the shell namespace and the shell's use of special directories. This chapter also explains how to work with the taskbar as well as how to create shortcuts. And although the console isn't strictly part of the Explorer shell, this chapter covers it as well. The Windows CE console isn't on all Windows CE systems. For example, the Pocket PC doesn't include console support. Although Windows CE doesn't support the full character mode API found in Windows XP, you can still write fairly complete console applications.