1. Theoretical part. Getting acquainted with the Visual Component Library.
1.1. Purpose and structure of VCL.
1.2. VCL components.
1.3. VCL class hierarchy.
1.4. Component types.
1. Theoretical part. Getting acquainted with the Visual Component Library.
1.1. Purpose and structure of the VCL.
The Visual Component Library is a library integrated into the development environment. Its main purpose is to manipulate visual component classes during the design phase. The behavior and appearance of components are determined as the application is developed, although they can be modified during program execution. The VCL's mission is to hide the complexities of Windows' low-level API functions from the programmer.
1.2. VCL components.
Components are the "building blocks" from which the program interface is constructed. Components gradually provide the appearance of the application and define its behavior and features. A VCL component is represented by an object that the programmer can drag from the component palette onto a form. Once a component is placed, the programmer can control its appearance (unless the component is an "invisible" or "faceless" class.
The TObject class is the fundamental ancestor of all other classes. It is this class that has the Sender parameter, which allows event handlers to identify almost any event source object.
The TPersistent class is an abstract class derived from TObject. All classes derived from TPersistent will have the ability to assign and be thread-safe.
The class has the following methods:
Assign, AssignTo - Copies an object to another object of the same class.
defineProperties - Defines the procedure for loading and saving special information in the stream (by default, only well-known properties are saved - __published).
getOwner - Returns the owner of this object.
The TComponent class is derived from TPersistent. This class gives all components the following features::
The appearance of components on the palette and their management in the form editor.
The ability to own and maintain other components.
Special flow characteristics.
The possibilities of pops
1.1. Purpose and structure of VCL.
1.2. VCL components.
1.3. VCL class hierarchy.
1.4. Component types.
1. Theoretical part. Getting acquainted with the Visual Component Library.
1.1. Purpose and structure of the VCL.
The Visual Component Library is a library integrated into the development environment. Its main purpose is to manipulate visual component classes during the design phase. The behavior and appearance of components are determined as the application is developed, although they can be modified during program execution. The VCL's mission is to hide the complexities of Windows' low-level API functions from the programmer.
1.2. VCL components.
Components are the "building blocks" from which the program interface is constructed. Components gradually provide the appearance of the application and define its behavior and features. A VCL component is represented by an object that the programmer can drag from the component palette onto a form. Once a component is placed, the programmer can control its appearance (unless the component is an "invisible" or "faceless" class.
The TObject class is the fundamental ancestor of all other classes. It is this class that has the Sender parameter, which allows event handlers to identify almost any event source object.
The TPersistent class is an abstract class derived from TObject. All classes derived from TPersistent will have the ability to assign and be thread-safe.
The class has the following methods:
Assign, AssignTo - Copies an object to another object of the same class.
defineProperties - Defines the procedure for loading and saving special information in the stream (by default, only well-known properties are saved - __published).
getOwner - Returns the owner of this object.
The TComponent class is derived from TPersistent. This class gives all components the following features::
The appearance of components on the palette and their management in the form editor.
The ability to own and maintain other components.
Special flow characteristics.
The possibilities of pops
