COM+ Programming With Visual Basic

The importance of a book like COM+ Programming with Visual Basic lies in the fact that the Visual Basic programming environment is designed to hide as many low-level system details as possible. While this approach can speed development time by letting you focus on the task at hand, it actually hinders the process when it obscures details you need to understand or control. Such is often the case for programmers who are developing components that take advantage of COM+ services. COM+ Programming with Visual Basic takes aim squarely at the information needs of these developers.

For instance, despite the marketing hype about COM+ as the new and improved version of COM, classic COM is very much the foundation on which COM+ is built: COM+ components are a particular kind of COM component. Visual Basic hides almost all COM implementation details; yet it is precisely in the area of COM+ programming that these hidden details are most important. Therefore, we've devoted significant content to exploring COM internals:

• Interface-based programming


• How COM interfaces work internally


• How COM components are activated


• How versioning COM components works in Visual Basic

The second section focuses on incorporating individual COM+ services, like transaction support, security, and asynchronous operations, into applications. The author concludes by discussing what you need to learn to transition to Microsoft's coming .NET framework.

Regardless of what lies ahead for .NET, many distributed systems are being built today with COM+. COM+ Programming with Visual Basic focuses on topics relevant to distributed applications that are here to stay:

• How to use interfaces


• Passing objects by reference or by value


• What it means to have multithreaded applications


• How declarative programming works


• How to program within a distributed transaction


• How to add role-based security to applications

There's simply no other documentation available for much of what's in
COM+ Programming with Visual Basic. It's destined to be the resource behind the most robust, efficient, high-performance COM+ applications.

《COM+ Programming with Visual Basic》這本書的重要性在於，Visual Basic 程式設計環境的設計目標是盡可能隱藏低層系統細節。這種方法可以加快開發速度，讓你專注於手頭的任務，但當它遮蔽了你需要理解或控制的細節時，實際上會阻礙過程。這通常是開發利用 COM+ 服務的元件的程式設計師所面臨的情況。《COM+ Programming with Visual Basic》正是針對這些開發人員的資訊需求而撰寫的。

例如，儘管有關 COM+ 是 COM 的新版本並且改進了的行銷宣傳，但經典的 COM 仍然是 COM+ 建立在其上的基礎：COM+ 元件是一種特定類型的 COM 元件。Visual Basic 幾乎隱藏了所有 COM 的實作細節；然而，正是在 COM+ 程式設計的領域中，這些隱藏的細節最為重要。因此，我們在探索 COM 內部結構方面投入了大量內容：

- 基於介面的程式設計
- COM 介面的內部運作方式
- COM 元件的啟動方式
- Visual Basic 中的 COM 元件版本控制方式

第二部分專注於將個別的 COM+ 服務（如交易支援、安全性和非同步操作）整合到應用程式中。作者最後討論了你需要學習的內容，以過渡到微軟即將推出的 .NET 框架。

無論 .NET 的未來如何，今天仍然有許多分散式系統正在使用 COM+ 進行建構。《COM+ Programming with Visual Basic》專注於與分散式應用程式相關的主題，這些主題將會持續存在：

- 如何使用介面
- 以參考或值的方式傳遞物件
- 多執行緒應用程式的意義
- 宣告式程式設計的運作方式
- 如何在分散式交易中進行程式設計
- 如何為應用程式添加基於角色的安全性

對於《COM+ Programming with Visual Basic》中的許多內容，簡直沒有其他可用的文件。它注定成為最強大、高效率、高性能的 COM+ 應用程式的資源。