Delphi Tutorials and Sample Code - VCL & FMX

VCL

How to Retrieve Printer Information in Delphi: Using DeviceCapabilities, LOGPIXELSX, and Related Techniques

A detailed guide on retrieving printer resolution, paper sizes, and printable areas in Delphi. Includes practical examples using DeviceCapabilities, GetDeviceCaps, LOGPIXELSX, and DMPAPER constants to improve the accuracy and reliability of printing operations.

VCL

How to Perform Printing in Delphi: Practical Examples Using TPrinter, Canvas, and TextOut

A detailed guide to outputting text and images to a printer in Delphi, using TPrinter and Canvas. Includes practical source code examples for TextOut, TextRect, bitmap printing, and other essential printing techniques.

VCL

Parallel Programming with the TTask Class — Delphi Source Code Collection

A practical guide to parallel programming with the TTask class, explained through sample source code for prime number detection.

VCL

Retrieving the Display (Monitor) Scaling Settings in Windows — Delphi Source Code Collection

A sample-based explanation of how to retrieve the display scaling settings in Windows using Delphi.

VCL

How to Create a Custom On‑Screen Touch Keyboard in Delphi keybd_event and IME Control Supported

A detailed guide on creating a custom on‑screen (touch‑enabled) keyboard in Delphi, including keybd_event usage, IME control, and CreateParams configuration. Also covers how to handle cases where the default Windows on‑screen keyboard does not appear.

VCL

How to Control Clipping and Window Shapes in Delphi Using Regions Guide to CreateRectRgn and CreateEllipticRgn

A detailed guide on using Regions in Delphi (rectangular, elliptical, and polygonal) to perform image clipping and modify window shapes, complete with sample code using APIs such as CreateRectRgn and CreateEllipticRgn.

VCL

Creating a Resident Task Tray Application in Delphi Preventing Multiple Instances and Handling TaskbarCreated

A step‑by‑step guide to building a resident task tray application in Delphi, complete with source code. Covers preventing multiple instances, handling TaskbarCreated, processing WM_QUERYENDSESSION, and other techniques for creating a stable Windows background application.

String Conversion in Delphi Using LCMapStringEx: Half‑Width/Full‑Width, Hiragana/Katakana, Uppercase/Lowercase

A practical guide to using the Windows API LCMapStringEx in Delphi to convert strings between half‑width and full‑width characters, hiragana and katakana, and uppercase and lowercase. Includes clear explanations and sample code to help you implement reliable text‑conversion features in your applications.

VCL

Dragging Windows and Panels in Delphi: How to Use ReleaseCapture and SC_MOVE

A guide to moving forms and TPanels by mouse drag in Delphi’s VCL environment. This article explains how to implement window dragging using the Windows API functions ReleaseCapture and SendMessage(SC_MOVE), along with practical handling of TMouseButton events.

VCL

Get the Full Path of Windows Special Folders in Delphi | SHGetSpecialFolderPath Guide

Learn how to retrieve the full path of Windows special folders—such as Desktop, My Documents, and Application Data—using the SHGetSpecialFolderPath API in Delphi. Includes clear explanations and practical sample code.

VCL

Opening Windows Explorer with the ShellExecute API in Delphi | Practical Code Examples

Learn how to open Windows Explorer from Delphi using the ShellExecute API—either by opening a specific directory or highlighting a selected file. This guide includes clear explanations and practical sample code.

VCL

How to Create a Startup Shortcut (.lnk) in Delphi | Windows Auto‑Launch Implementation Guide

Learn how to create a shortcut (.lnk file) in the Windows Startup folder using Delphi to automatically launch your application at login. This guide explains the process with clear sample code using IShellLink and IPersistFile.

VCL

Improving Image Scaling Quality in Delphi with StretchBlt and SetStretchBltMode (HALFTONE)

Learn how to improve image scaling quality in Delphi using the StretchBlt API together with SetStretchBltMode(HALFTONE). This guide explains the differences from TCanvas.StretchDraw, how to work with HDCs, and includes practical sample code.

VCL

Controlling Windows with SetWindowPos in Delphi | Z-Order, Topmost, and SWP Flags Explained

Learn how to use the Windows API SetWindowPos in Delphi to control window position, size, and Z-order. Includes examples for topmost windows (HWND_TOPMOST), sending windows to the back (HWND_BOTTOM), non-activating updates (SWP_NOACTIVATE), and a clear overview of common SWP flags

VCL

Retrieving Process Lists and Forcibly Terminating Processes — Delphi Source Code Collection

A practical guide showing how to retrieve a process list in Delphi using the QueryFullProcessImageNameW API and forcibly terminate processes with the TerminateProcess API, complete with sample source code.

VCL, FMX

Drawing on the Delphi Canvas｜Sample Code for Shapes and Text Rendering with TBitmap and TCanvas (VCL/FMXL)

A complete guide to drawing shapes and text on the Delphi Canvas using TBitmap and TCanvas. Includes VCL and FMX sample code, FillRect and TextRect usage, TBitmap settings, integration with TImage, and geometric pen techniques.

VCL, FMX

Rotate a TBitmap Image and Draw It on a Canvas (VCL & FMX) – Delphi Source Code Examples

Explains how to rotate a TBitmap image around any point at any angle and draw it on a Canvas in both VCL and FMX, with clear Delphi sample source code.

VCL

Direct2D Canvas Rendering in Delphi: Controlling Anti-Aliasing and Alpha Blending

A practical guide to using Delphi’s TDirect2DCanvas to implement anti‑aliased rendering and alpha‑blend transparency control. This article explains how to improve the quality of RoundRect and line drawing through proper settings, and includes examples of exporting bitmaps using TImage.

VCL

How to Display PSD Files in Delphi Installing and Using the GraphicEx Library

To display Photoshop PSD files in Delphi, the GraphicEx library is a practical solution. This article explains how to download and configure GraphicEx, and provides sample source code for rendering PSD images in TImage. It also covers reading layer information and saving bitmaps.

VCL

Using PDFium in Delphi: PDF Rendering, Text Extraction, and Image Conversion with Sample Code

A detailed guide on how to use PDFium in Delphi to render PDF files, extract text, and convert pages to images. Includes download sources for the required DLLs and libraries, implementation steps for VCL applications, and complete sample code. Verified to work with Delphi 12 CE

VCL

Registering Global Hotkeys in Delphi with RegisterHotKey — Handling WM_HOTKEY and Window Control Examples

Explains how to register system-wide global hotkeys in a Delphi VCL application using the RegisterHotKey API. Covers handling WM_HOTKEY messages, managing IDs with GlobalAddAtom, bringing windows to the front with SetWindowPos, and includes practical code examples.

VCL

How to Receive Drag-and-Drop Files in Delphi VCL — WM_DROPFILES and DragQueryFile Implementation Examples

A detailed guide on how to receive files and folders dragged from Explorer into a Delphi VCL application using WM_DROPFILES and DragQueryFile. Includes sample code, message handling with ApplicationEvents, and methods for displaying dropped files in a ListBox.

FMX

Handling Drag-and-Drop Files in Delphi FMX — Implementing WM_DROPFILES and DragQueryFile

Explains how to receive files and folders dragged from Windows Explorer into a Delphi FMX application using WM_DROPFILES and DragQueryFile. Includes sample code, replacing the Window Procedure with CallWindowProc, and displaying dropped items in a ListBox.

VCL

How to Drag and Drop Files in Delphi VCL — TOleDragPanel and DoDragDrop Implementation Examples

A step-by-step guide to implementing file drag-and-drop in Delphi VCL using the TOleDragPanel class and the DoDragDrop API. Includes sample code demonstrating integration with Windows APIs such as ILCreateFromPath and QueryContinueDrag, along with examples of handling OnDrop events.

VCL

Using the Browser Speech Recognition API from Delphi with WebView4Delphi (WebView2) – Delphi Source Code Collection

A step-by-step guide showing how to use the browser SpeechRecognition API from Delphi via WebView4Delphi (WebView2), complete with sample source code.

VCL

Using the Browser Geolocation (GPS) API from Delphi with WebView4Delphi (WebView2) – Delphi Source Code Collection

A step-by-step guide showing how to use the browser Geolocation (GPS) API from Delphi via WebView4Delphi (WebView2), complete with sample source code.

VCL

Creating a Service Application in Delphi

Explains how to create a service application that starts automatically when the OS boots, even without user logon, and how to register the service in Windows using sample source code.

VCL, Windows API

Sending Ping Requests in Delphi (IcmpSendEcho API)

How to Send Ping Requests in Delphi Using the IcmpSendEcho API

VCL

Parsing JSON Responses from REST APIs in Delphi — Implementing a Zip Code Lookup Using TRESTClient and TJsonObject

This article explains how to perform REST API communication in Delphi and parse JSON responses using TJsonSerializer, TJsonTextReader, and TJsonObject. Through an implementation example using the ZipCloud API, it demonstrates how to use TRESTClient, TRESTRequest, and TRESTResponse, along with important considerations when handling different JSON structures

Sending GET and POST Requests with Delphi’s TNetHTTPClient and Retrieving Web Content

This article explains how to use Delphi’s TNetHTTPClient to send GET and POST requests to a web server and handle cookies, with sample source code.

VCL

How to Read QR Codes from a Webcam in Delphi｜Complete Guide Using ZXing.Delphi + DSPack

A comprehensive, step‑by‑step guide to reading QR codes and barcodes from a webcam in Delphi using ZXing.Delphi and DSPack. Includes form design, component setup, event handling, and full source code examples to help you implement scanning quickly and reliably.

Installing DSPack: A Delphi Library for Easily Working with DirectShow

A guide to installing DSPack, a Delphi library that makes DirectShow (for handling webcams and creating videos) easy to use.

VCL

Reading Illuminance (Lux) from a Light Sensor (VCL) — Delphi Source Code Collection

A sample‑based explanation of how to read illuminance (in lux) from a PC equipped with a light sensor using Delphi.

VCL

Reading and Writing NFC Cards (NXP NTAG215) with PaSoRi and Delphi – Windows Sample Code Collection

This article explains how to read and write NFC cards (NXP NTAG215) using PaSoRi (RC-S380) and Delphi in a Windows environment (winscard.dll and ScardTransmit), with sample code included. While UID can be retrieved from other IC cards as well, this article focuses specifically on NTAG215.

VCL

Delphi NFC Programming with PaSoRi (RC-S3800): Read and Write Strings and URLs

Step-by-step guide to using Delphi with the PaSoRi RC-S3800 NFC reader. Learn how to read and write strings, URLs, and UID data from IC cards, with complete source code examples and execution instructions.

VCL

Play Microphone Audio in Near Real Time

A step‑by‑step explanation with sample Delphi source code showing how to play microphone audio to the speakers in near real time.

VCL

Create a Voice Changer in Delphi FFT + Pitch Shifting Sample Code

Explains how to capture microphone input in Delphi, apply FFT‑based pitch shifting, and play the processed audio in real time. Includes full source code.

VCL

Record Microphone Audio in Delphi and Save as a WAV File

Create a Delphi application that records microphone audio using waveIn and saves it as a WAV file. Includes complete source code and explanations.

VCL

Retrieving SMART Data in Delphi｜How to Check SSD/HDD Health Status

A step‑by‑step guide on how to retrieve SMART data from SATA‑connected SSDs and HDDs using Delphi, including sample source code. Supports checking drive health status and reading attribute values.

VCL

How to Retrieve SMART Information from NVMe SSDs in Delphi｜Health Log & IOCTL Usage Example

A guide to retrieving SMART information (Health Information Log) from NVMe‑connected SSDs using Delphi. Includes an implementation example using IOCTL_STORAGE_QUERY_PROPERTY for storage diagnostics on Windows.

VCL

Wake-on-LAN in Delphi Send Magic Packets to Power On Remote PCs

Learn how to send Wake-on-LAN (WOL) magic packets in Delphi to power on remote PCs. Includes a simple example and full source code.

VCL

Reading Aloud the Entered Text — Delphi Source Code Collection

A sample‑based explanation of how to create an application that reads aloud (speaks) the text entered by the user.

VCL

Retrieving Keyboard, Mouse, and Joystick Input

A sample‑based explanation of how to obtain the current state of the keyboard, mouse, and joystick (gamepad) controllers—essential for game development.

VCL

Playing a Sound at a Specified Frequency in Delph

A step‑by‑step sample showing how to play a tone at a specified frequency using Winapi.Windows.Beep in Delphi.

VCL

Playing MIDI Sounds in Delphi — A Practical Guide to midiOutShortMsg

A practical guide to playing MIDI sounds in Delphi using midiOutShortMsg, including note on/off, program changes, chords, and fully working sample code.

FFT in Delphi: Fast Fourier Transform Tutorial with Window Functions and Analysis Code

Learn how to implement FFT (Fast Fourier Transform) in Delphi with complete sample code. Covers Hanning, Hamming, Blackman–Harris window functions, amplitude and frequency analysis, and handling real and imaginary components. Ideal for signal processing and spectrum analysis in Delphi.

Implementing a UTF‑8 to UTF‑16LE Conversion Function in Delphi

Delphi can convert UTF‑8 to UTF‑16LE using TEncoding.UTF8.GetString, but it fails when invalid byte sequences are present. This article explains a safer conversion method that handles malformed UTF‑8 as gracefully as possible, with complete source code.

FMX

Building a 3D Simulator in Delphi FMX — Controlling a Drone‑Like Object with Viewport3D

This guide explains how to build a 3D simulator in Delphi FMX using , including how to control a drone‑like object in a 3D space. It covers coordinate handling, movement logic, and includes practical example code.

VCL

Image Filters in Delphi (VCL) — Unsharp Mask, Gaussian Blur, Smoothing, and Salt‑and‑Pepper Noise Removal

This article explains how to apply common image filters to a TBitmap in Delphi (VCL), including Unsharp Mask (sharpening), Gaussian blur (noise reduction), smoothing/average blur, median filtering for salt‑and‑pepper noise removal, and grayscale conversion, with complete sample source code.

VCL

Implementing Image Perspective Transformation (Homography) in Delphi — Converting Trapezoid and Parallelogram Regions with Code Examples

This guide explains how to perform perspective transformation (homography) in Delphi to correct trapezoid and parallelogram regions in images. Includes VCL application structure using TScrollBox and ExtCreatePen, along with practical code examples. Also covers how to load JPG/PNG files and apply the transformation step by step.

Controlling Excel from Delphi: Practical OLE Automation Examples with OLEVariant and CreateOleObject

Learn how to control Excel from Delphi using OLEVariant and CreateOleObject. This guide covers practical examples for setting cell values, applying formatting and borders, configuring print settings, and saving Excel files—ideal for real‑world business applications.

VCL

Drawing Charts in Delphi with TChart: Line, Bar, and Pie Graphs Using TeeChart, AddXY, and Series

Learn how to draw line charts, bar charts, and pie charts in Delphi using the TChart (TeeChart) component. This guide explains how to use AddXY, TLineSeries, and Series effectively, with practical VCL examples and sample code.

Fully Implemented AES Encryption in Delphi: Mam.AES.pas with OpenSSL‑Compatible CBC, CTR, and ECB Modes

Mam.AES.pas is a pure‑Delphi AES encryption/decryption unit that requires no external DLLs.It supports AES‑128/192/256 in CBC, CTR, and ECB modes, provides OpenSSL‑compatible salt generation, and includes key and IV hashing for secure, real‑world encryption workflows.

VCL

Working with WebP, SVG, and PDF in Delphi Using Skia4Delphi — A Practical sk4d.dll Guide

This guide explains how to use Skia4Delphi in Delphi to handle WebP, JPEG, SVG, and PDF processing. Includes practical examples for converting WebP/JPEG images, rendering SVG graphics, generating PDF files, and properly configuring sk4d.dll.

VCL

WebP Image Conversion in Delphi — How to Use the delphi-webp Library (with Sample Code)

This guide explains how to convert images to WebP format in Delphi using the delphi-webp library. Includes installation steps, DLL placement, and Pascal code examples. Supports converting JPG/PNG to WebP and WebP back to PNG.