Introduction to Delphi Grade 10

Delphi is a visual programming environment — you design the screen AND write the code. You drag components onto a form to build the interface, then write Pascal code to make it all work. This page covers the IDE layout, components, naming, events, and your first program.

The Delphi IDE — What You See When You Open It

When you open Delphi, this is what you will see. It might look overwhelming at first — but each area has one clear job:

Delphi 11 — Design View (this is where you build the form your user will see)

Object Inspector — set properties like Name, Caption, Color

Tool Palette — drag components from here onto the form

Switching to Code View

Press F12 to toggle between the Design View (what you see above) and the Code View (where you type your Delphi code).

Code View — this is the Delphi code structure that is automatically created for you

The Delphi IDE Layout

The Integrated Development Environment (IDE) is where you write, design and run your programs. Think of it as your workshop — every tool you need is right there.

Key IDE Panels

Step-by-Step: Creating Your First Project

1. File → New → Windows VCL Application — creates a blank Form (TForm).
2. Place components by clicking them in the Tool Palette, then clicking on the form.
3. Set properties in the Object Inspector (e.g. change a button's Caption).
4. Double-click a button to go to Code View and write the event handler.
5. File → Save All (Ctrl+Shift+S) — save in a NEW dedicated folder.
6. Press F9 to compile and run.

Visual Component Reference

Components are the building blocks placed on a form. Each is an object with properties and events. Here is what the most common ones look like:

Naming Convention

Every component gets a prefix that indicates its type, followed by a meaningful name. This makes code readable.

Event-Driven Programming

Delphi programs are event-driven — code only runs when something HAPPENS (an event), like pressing a button, typing in a box, or a timer ticking.

How to Create an Event Handler

1. In Design View, double-click a button to create its OnClick handler automatically.
2. For other events, go to the Events tab in the Object Inspector and double-click next to the event name.
3. Delphi creates a skeleton procedure. Write your code between begin and end.
4. Never change the procedure header — only add code inside.

procedure TForm1.btnCalculateClick(Sender: TObject);
begin
  // Your code goes here
  ShowMessage('Button clicked!');
end;

ShowMessage and InputBox

ShowMessage displays a pop-up with a message. InputBox pops up a window asking the user to type something. Both are modal — the program pauses until the user responds.

ShowMessage('Hello world!');
ShowMessage('Result: ' + IntToStr(iAnswer));

// Returns a string
sName   := InputBox('Name', 'Enter your name:', '');

// Convert to integer
iNum    := StrToInt(InputBox('Number', 'Enter a number:', ''));

// Convert to real
rAmount := StrToFloat(InputBox('Amount', 'Enter amount:', ''));

// Get first character only
cClass  := InputBox('Class', 'Enter class:', '')[1];

Components — Properties

Properties control how a component looks and behaves. Set them in the Object Inspector or through code.

Setting Properties in Code

Format: ComponentName.Property := Value;

Form1.Height        := 500;
Button1.Caption     := 'Register';
Label1.Font.Color   := clGreen;
Shape1.Brush.Color  := clRed;
Shape1.Top          := 20;
Shape1.Left         := 20;

Methods

Methods are pre-written operations that perform tasks on components. Format: ComponentName.Method;

Syntax Rules