Learn DELPHI-VCL with Real Code Examples

VCL is an object-oriented framework built on top of Delphi's Object Pascal.

It provides visual components like forms, buttons, grids, and menus, and non-visual components like timers, database connectors, and threads.

VCL simplifies event-driven programming with properties, methods, and events.

Widely used for desktop, database, and enterprise application development on Windows.

Supports both 32-bit and 64-bit Windows targets, and integrates with FireMonkey for cross-platform applications.

Forms and controls

Event handling system

Property and method binding

Component streaming and persistence

Database-aware controls

Forms and controls

Events and event handlers

Properties and methods

Component hierarchy

Database-aware controls and connections

Project (.dpr) file

Unit (.pas) files

Form (.dfm) files

Resource files (.res)

External component libraries

Create a new VCL Forms Application

Drag-and-drop controls onto the form

Set properties and link event handlers

Add non-visual components as needed

Compile and run application

Beginner: Simple calculator or notepad app

Intermediate: Database form with grid and queries

Advanced: Multi-threaded enterprise application

Expert: Custom component development

Architect: Large-scale modular VCL application with plug-ins

VCL vs FireMonkey: VCL is Windows-only and native; FMX is cross-platform

VCL vs .NET WinForms: Similar rapid Windows GUI development

VCL vs WPF: VCL is more lightweight, WPF has richer graphics

VCL vs Qt: Qt is cross-platform and C++/Python friendly

VCL vs Lazarus LCL: VCL is commercial, mature, and feature-rich

Delphi 1 (1995) - initial VCL release

Delphi 3–5 - database and Win32 enhancements

Delphi 7 (2002) - stable VCL desktop platform

Delphi XE series - Unicode support and 64-bit compilation

Delphi 10.x - modern Windows 10/11 support and FMX integration

VCL - Visual Component Library

Form - main window container

Component - visual or non-visual element

Event - callback triggered by user or system

Property - configurable attribute of a component