Visual Component Library (VCL)

視覺化元件程式庫( Visual Component Library, VCL ) 是 Borland 所發展出來的, 包含 Objects, Components, Routines, Types, Constants and Variables 等五大部分。底下的說明是從 Borland C++ Builder Help 所寫的說明文字。

Objects
An object consists of methods, and in many cases, properties, and events. Properties represent the data contained in the object. Methods are the actions the object can perform. Events are conditions the object can react to. All objects descend from the ancestor object TObject.

Components
Components are visual objects that you can manipulate at design time. All components descend from TComponent.

Routines
Global routines are the procedures and functions from the runtime library and from the VCL. These routines are not part of a class, but can be called either directly or from within class methods.

Types
The types described in the Help are used as return types and parameter types for object methods, properties and events, and for global routines. In many cases, types are documented in the entry for the method, property, event or global routine in which they are used.

Constants and Variables
The constants and variables defined in the Help are declared in the runtime library and in the VCL. Some of these are instantiations of objects. Examples are the Application and Screen variables. Others represent routines that provide the underlying implementation of other methods or global routines. Examples include the AnsiResemblesProc and RegisterComponentsProc variables. Still other variables and constants represent information that can vary with the system or platform, such as the DateSeparator variable and PathDelim constant.

Borland C++ Builder 是 Borland 針對 C++ 程式語言所開發的快速應用程式開發工具 ( Rapid Application Development, RAD ), Borland 為 C++ 加入了許多的視覺化元件, 配合整合開發環境 ( Integrated Development Environment, IDE ), 推出了 Borland C++ Builder 這個產品, 加速了一個視窗應用程式的開發。