Delphi Programming for Dummies: A Practical Guide to Creating Windows Applications with Delphi
Delphi Programming for Dummies
Are you interested in learning a powerful and versatile programming language that can help you create native applications for Windows, Linux, macOS, iOS, and Android? If so, then you should consider Delphi programming. In this article, we will introduce you to the basics of Delphi programming, show you how to get started with the Delphi IDE, and guide you through some of the most common tasks and features of Delphi development. By the end of this article, you will have a better understanding of what Delphi programming is and how you can use it to build amazing applications.
Delphi Programming For Dummies 317.pdf
What is Delphi programming?
Delphi is a general-purpose programming language and a software product that uses the Delphi dialect of the Object Pascal programming language and provides an integrated development environment (IDE) for rapid application development of desktop, mobile, web, and console software, currently developed and maintained by Embarcadero Technologies.
A brief history of Delphi
Delphi was originally developed by Borland as a rapid application development tool for Windows as the successor of Turbo Pascal. Delphi added full object-oriented programming to the existing language, and the language has grown to support generics, anonymous methods, closures, and native Component Object Model (COM) support.
Delphi and its C++ counterpart, C++Builder, are interoperable and jointly sold under the name RAD Studio. There are Professional, Enterprise, and Architect editions, with the higher editions having more features at a higher price. There is also a free-of-charge Community edition, with most of the features of Professional, but restricted to users and companies with low revenue.
The features and benefits of Delphi
Delphi supports rapid application development (RAD). Prominent features are a visual designer and two application frameworks, VCL for Windows and FireMonkey (FMX) for cross-platform development.
Delphi uses the Pascal-based programming language Object Pascal created by Anders Hejlsberg for Borland (now IDERA) as the successor to Turbo Pascal. It supports native cross-compilation to many platforms including Windows, Linux, iOS and Android.
To better support development for Microsoft Windows and interoperate with code developed with other software development tools, Delphi supports independent interfaces of Component Object Model (COM) with reference counted class implementations, and support for many third-party components.
Delphi includes a code editor, a visual designer, an integrated debugger, a source code control component, and support for third-party plugins. The code editor features Code Insight (code completion), Error Insight (real-time error-checking), and refactoring. The visual forms designer has the option of using either the Visual Component Library (VCL) for pure Windows development or the FireMonkey (FMX) visual framework for cross-platform responsive UIs.
Database support is a key feature and is provided by FireDAC (Database Access Components).
Delphi is known for its fast compilation speed, native code, and developer productivity. 
The Delphi dialect of Object Pascal
The Delphi dialect of Object Pascal is a high-level programming language that also supports object-oriented programing. The programming language is able to incorporate the low-level and assembly-level language codes, which enable it to have access to the machine learning as a service hardware.
The syntax of Object Pascal is similar to that of standard Pascal but with some extensions such as classes, interfaces, properties, exceptions, generics etc.
Here is an example of a simple class declaration in Object Pascal:
```pascal type TPerson = class private FName: string; FAge: Integer; public constructor Create(AName: string; AAge: Integer); function GetInfo: string; property Name: string read FName; property Age: Integer read FAge; end; ``` How to get started with Delphi programming?
To start developing applications with Delphi programming, you need to download and install the Delphi IDE from Embarcadero's website. You can choose from different editions depending on your needs and budget. You can also try out the free Community edition if you qualify for it.
The Delphi IDE and its components
The Delphi IDE is a graphical user interface that allows you to create, edit, compile, debug, and deploy your applications. The IDE consists of several components such as:
- The Project Manager: This is where you can manage your project files, settings, and dependencies. - The Form Designer: This is where you can design your user interface by dragging and dropping visual components from the Tool Palette onto your forms. - The Code Editor: This is where you can write your source code using Object Pascal syntax. - The Object Inspector: This is where you can view and modify the properties and events of your selected components. - The Structure View: This is where you can see the hierarchy and relationships of your forms and components. - The Debugger: This is where you can set breakpoints, watch variables, evaluate expressions, and step through your code execution. How to create a simple Hello World application in Delphi
To create a simple Hello World application in Delphi, follow these steps:
- Launch the Delphi IDE and select File > New > VCL Application - Delphi. - A new project will be created with a blank form named Form1. - In the Form Designer, select Label from the Tool Palette and drag it onto the form. - In the Object Inspector, change the Caption property of Label1 to Hello World. - Select File > Save All and save your project files in a folder of your choice. - Select Run > Run or press F9 to compile and run your application. - A window will appear with your label displaying Hello World. How to use the visual designer and the code editor
The visual designer and the code editor are two essential tools for developing applications in Delphi. You can use them together or separately depending on your preference.
The visual designer allows you to create your user interface by using visual components such as buttons, edit boxes, list boxes, menus etc. You can customize their appearance and behavior by changing their properties and events in the Object Inspector.
The code editor allows you to write your business logic by using Object Pascal syntax. You can access your components' properties and methods by using dot notation such as Button1.Caption or Edit1.Text.
You can switch between the visual designer and the code editor by using tabs at the bottom of the IDE or by pressing F12.
You can also use both views simultaneously by using split view or floating windows.
How to debug and run your Delphi application
To debug and run your Delphi application, you can use several tools provided by the IDE such as:
- The Run menu: This is where you can find commands such as Run, Pause, Stop, Step Into, Step Over etc. - The Debug menu: This is where you can find commands such as Breakpoints, Watches, Evaluate/Modify etc. - The Debug toolbar: This is where you can find buttons for common debugging actions such as Run, Pause, Stop etc. How to develop cross-platform applications with Delphi?
One of the main advantages of Delphi programming is that you can create cross-platform applications that can run on multiple devices and operating systems with minimal changes to your code. This is possible thanks to the two application frameworks that Delphi provides: VCL and FMX.
The VCL and FMX frameworks
VCL stands for Visual Component Library and is a set of visual and non-visual components that are designed for Windows development. VCL components use the native Windows controls and APIs to provide a native look and feel and high performance. VCL components can also be used to create Windows services, DLLs, console applications, and COM objects.
FMX stands for FireMonkey and is a set of visual and non-visual components that are designed for cross-platform development. FMX components use a custom rendering engine that can draw the same user interface on different platforms and devices. FMX components can also be used to create 3D graphics, animations, multimedia, and games.
To choose between VCL and FMX, you need to consider your target platforms and your application requirements. If you only need to develop for Windows, then VCL might be a better choice as it offers more compatibility and functionality with the Windows platform. If you need to develop for multiple platforms, then FMX might be a better choice as it offers more flexibility and portability across devices.
How to design responsive UIs with FireMonkey
FireMonkey is a powerful framework that allows you to create responsive UIs that can adapt to different screen sizes, resolutions, orientations, and pixel densities. FireMonkey also supports high-DPI displays and multi-monitor setups.
To design responsive UIs with FireMonkey, you can use the following features:
- The Form Designer: This is where you can design your user interface by dragging and dropping visual components from the Tool Palette onto your forms. You can use the Align, Anchor, Margins, and Padding properties to position and resize your components relative to their parent containers. You can also use the AlignWithMargins and Scaled properties to adjust your components according to the form's scale factor. - The Style Designer: This is where you can customize the appearance of your components by editing their style elements such as colors, fonts, images, shapes etc. You can also create and apply different styles for different platforms and devices using style sets and style books. - The Multi-Device Preview: This is where you can preview how your user interface will look on different platforms and devices without having to compile and run your application. You can select from a list of predefined devices or add your own custom devices. - The Master-Detail Layout: This is where you can create a master-detail layout that shows a list of items on one side and the details of the selected item on the other side. You can use the MasterButton and DetailPanel components to implement this layout and set their properties to control how they behave on different screen sizes and orientations. How to target different platforms with Delphi
To target different platforms with Delphi, you need to use the Project Manager and the Deployment Manager tools.
- The Project Manager: This is where you can manage your project files, settings, and dependencies. You can also add or remove target platforms for your project by right-clicking on the Target Platforms node and selecting Add Platform or Delete Platform. You can then select the platform you want to target from a list of supported platforms such as Windows, Linux, macOS, iOS, Android etc. - The Deployment Manager: This is where you can manage the files that are required for deploying your application to your target platforms. You can add or remove files by right-clicking on the Deployment node and selecting Add Files or Delete Files. You can also set the remote path and permissions for each file by editing their properties in the Object Inspector. To compile and run your application on your target platform, you need to select the platform from the Project Manager or from the toolbar and then select Run > Run or press F9. You may also need to configure some additional settings such as SDKs, provisioning profiles, certificates etc depending on your target platform. How to connect your Delphi application to databases and web services?
Delphi provides several tools and components for connecting your application to databases and web services such as:
- The FireDAC database access components: These are a set of components that allow you to connect to various databases such as SQLite, InterBase, MySQL, Oracle, SQL Server etc. You can use the TFDConnection component to establish a connection to a database server and then use other components such as TFDQuery, TFDTable, TFDStoredProc etc to execute SQL commands and manipulate data. - The REST Client Library: This is a library that allows you to consume RESTful APIs and JSON data from web services such as Google Maps, Twitter, Facebook etc. You can use the TRESTClient component to specify the base URL of the web service and then use other components such as TRESTRequest, TRESTResponse, TRESTResponseDataSetAdapter etc to send requests and receive responses. - The RAD Server engine: This is an engine that allows you to create your own backend servers or modules using Delphi code. You can use RAD Server to expose RESTful APIs, JSON data, database access etc for your Delphi applications or other clients. Conclusion
In this article, we have covered some of the basics of Delphi programming and how you can use it to create cross-platform applications for desktop, mobile, web, and console platforms. We have also shown you how to use some of the most common tools and features of Delphi development such as:
- The Delphi IDE and its components - The visual designer and the code editor - The debugger and the run menu - The VCL and FMX frameworks - The FireDAC database access components - The REST Client Library - The RAD Server engine We hope that this article has given you a good introduction to Delphi programming and inspired you to explore more of its possibilities. Delphi is a powerful and versatile programming language that can help you create amazing applications with ease and efficiency.
What are some of the advantages of Delphi programming?
Some of the advantages of Delphi programming are: - It supports rapid application development (RAD) with a visual designer and two application frameworks (VCL and FMX). - It supports native cross-compilation to many platforms including Windows, Linux, iOS, Android, and Linux (x64). - It uses a Pascal-based programming language that is easy to learn and read. - It has a rich ecosystem of frameworks and support tools for various domains such as databases, web services, IoT, 3D graphics etc.
What are some of the challenges of Delphi programming?
Some of the challenges of Delphi programming are: - It may require some additional configuration and setup for targeting different platforms such as SDKs, provisioning profiles, certificates etc. - It may have some compatibility issues with some third-party libraries or components that are not updated or supported for newer versions or platforms. - It may have some performance or memory issues when dealing with large datasets or complex UIs.
What are some of the best resources for learning Delphi programming?
Some of the best resources for learning Delphi programming are: - The official documentation from Embarcadero Technologies: https://docwiki.embarcadero.com/RADStudio/en/Main_Page - The official blog from Embarcadero Technologies: https://blogs.embarcadero.com/ - The official YouTube channel from Embarcadero Technologies: https://www.youtube.com/user/EmbarcaderoTechNet - The LearnDelphi.org website: https://learndelphi.org/ - The Fearless Cross-Platform Development with Delphi book by David Cornelius: https://www.packtpub.com/product/fearless-cross-platform-development-with-delphi/9781800203822