Basics of programming in Embarcadero Delphi. RAD Studio XE5 for effective programming learning

This is our first Delphi lesson! All further lessons are designed for people familiar with the basics of the Pascal language and good computer skills. All lessons are “tailored” for Borland Delphi 7 ( not all, Embarcadero Rad Studio will be used in the future), however, can be studied using other, possibly newer Delphi environments, because The principle of application development is the same in all versions of Delphi. Many beginner lessons will come with additional video tutorials.

Let's open Borland Delphi 7 and explore appearance development environment interface:

In newer versions of Delphi, you can find the component palette in the form of a tree-like list, which is located in the right panel.

The “Form1” window is the appearance of your future program, which you can visually design. The design of the interface of the future program is based on components.
Components- these are a variety of buttons, windows, panels, text windows, checkboxes, etc. It is very difficult to list all the components.
All installed components located in the component palette, where they are all divided into tabs, such as “Standard”, “Additional”, “Win32” and others.
To the left of the “Form1” window there are two windows: “Object TreeView” and “Object Inspector”.
The “Object TreeView” window contains a list of all components placed on the form in the program. By selecting any of them, in the “Object Inspector” window we get the opportunity to change any parameters of the component selected in the “Object TreeView” window or in the “Form1” window. There we can change parameters such as the title of the program form, or the label on the button, etc.
Now let's talk about the components themselves. The components are divided into 2 sections:

• Visual
• Non-visual

Visual Components are components that we can see while working and designing a program. These include buttons, labels, text boxes, images, etc.
Not visual components - these are components that we do not see during operation, but we see during design. They are usually in the form of a small square panel with a picture inside. These include timers, a popup menu component (PopupMenu), and others. They are usually responsible for service or programmatic purposes.

Now let's learn how to create components and change their properties.

The TButton component is located in the “Standard” tab. This component plays the role of a very ordinary button, without which no program can do.
To create it, you need to left-click on the icon in the component palette and click on the place on the form where you want to place the component. By selecting a component with one click of the left mouse button, we can change its size.
Now let's select it with one click of the left mouse button and in the window
“Object Inspector” will find a parameter that will change the label on the button. This parameter is called "Caption". To the right of the parameter name we see a small text box that says “Button1”. This is the inscription on our button. Now let's change the label of this button to "This is my first button in DELPHI!".
Here's what I got:

Now let's look at the other parameters of the TButton component:

Now, having analyzed the properties of the TButton component, let's move on to the TCheckBox component in the Standard tab. On the form it looks like this:

Let's consider its parameters:
We will not specify component parameters that are similar to the previous ones (for example, a checkbox also has a Caption, just like a button, and the purpose of these two identical parameters is the same). Get used to such tables, because when studying new components, we will encounter such tables that will describe new unfamiliar parameters.

Now let's look at another TMemo component. It is also located on the “Standard” tab. Looks like this:

This is a multi-line text field.
Let's consider its parameters:

Well, there is still no way to bypass the TForm component. This is the same window that contains other components. To edit TForm properties, left-click on empty space forms. Here are a few TForm parameters.

In the tables above, I did not indicate quite a lot of parameters. We will gradually examine them in the following lessons.

I think I’ve told you enough about the properties of components, now let’s talk about their events.
For example: You click on a button, and it changes its Caption, or Left, or Visible parameter.
To do this, there is an “Events” tab in the “Object Inspector” window. In this tab we see a list of events that can occur with the component:

Having considered the most common events, let's move on to their creation.
In order to create an event for a component, you need to double-click with the left mouse button on text field, which is located to the right of the event name.
After this, a window will open in which you will need to enter the program code for that event. For example, so that when clicked, the Button1 component changes its label to “Pressed button” when processing the OnClick event.

It is writing the program code for the event that we will deal with in the next lesson. Don't forget to subscribe to the E-Mail newsletter for all the new and most interesting materials on the site.

• Recovery Mode

As an Embarcadero evangelist, I communicate with programmers quite intensively and to the limit of physical capabilities. Traffic is approximately 1000 people per year. At seminars, teachers who use Delphi and C++Builder in their teaching approach me. After getting acquainted with the capabilities of RAD Studio XE5, they ask: “Can I see a list of compelling arguments in favor of Delphi and C++Builder specifically for education?” The question is clear. People have been using these products to teach programming for years, watching their students achieve good level from a self-development point of view. But the “struggle” between technologies is also being waged in the field of education, and newfangled hobbies and flashy products with an unreasonably inflated image negatively affect people who are far from educational process, but influencing decision making. Out of respect for teachers, who often raise the young IT generation for little money, I present the following arguments, supported by personal experience of more than 15 years (schoolchildren, students, graduate students, teachers).

In the context of the ever-increasing role of teaching programming at all stages - from school to university - it is very important to choose an effective software environment. Let us consider in this capacity an integrated environment IDE development and a language basis using the example of RAD Studio XE5, which consists of Delphi XE5, C++Builder and HTML5 Builder. Respectively, language means This package solution includes Delphi/Pascal, C/C++ and a number of popular languages ​​and technologies for Web development. This combination is very effective if the goal of teaching programming is to develop the universal knowledge and skills necessary to create modern software (software) in the widest possible range of students.

The programming environment and language for developing primary skills based on basic knowledge should provide the lowest possible entry threshold. This is not just about school education. University students of any specialty are required to have an idea of ​​how modern software is developed. On the one hand, this is important for training at least competent users of already created systems. On the other hand, almost any area of ​​human activity, including the humanities, with in-depth study requires the development and use of complex application software. Law, linguistics, sociology, political science, etc. V modern form imply the ability of a specialist to see and understand the algorithms implemented in the functionality of the systems used programmatically.

Introduction to programming languages ​​should take place at school. But for various reasons, many students begin their studies at universities with a very vague understanding of programming; at least, they do not know how to create applications on their own. When talking about mass IT education in terms of learning programming, there is no need to make assumptions about the presence of any knowledge. That is why it is necessary to develop a unified approach to teaching programming both at school, and in secondary specialized, and in higher education institutions. Once again, the goal is to raise universal programming knowledge and application creation skills among all students nationally. Author's methods and targeted programs for the development of the most gifted students are not applicable to the general level. Languages ​​used and software environments with such training, it should not be considered when forming educational standards in schools, secondary specialized and higher educational institutions in areas not directly related to software development.

Practically ideal solution is the beginning of training in Delphi with the subsequent expansion of experience by using C++Builder to master professional skills and train specialists proficient in the most popular software creation technologies. The process of learning programming is divided into two complementary stages:

• primary skills and basic knowledge in Delphi;
• vocational training and access to highest level in C++Builder.

Delphi is based on Pascal, special language for quickly learning programming, so it has a simple and clear syntax that is not overloaded with special characters and does not require memorizing non-obvious and hard-to-read sequences.

The linguistic features of the Delphi/Pascal language are such that they use easily readable and interpretable character sequences as keywords. This allows you to “speak” program texts, and this is supported when using Delphi/Pascal.

We should not forget about the teachers. When performing practical tasks and laboratory work It is common practice to synchronously check and identify, as well as correct errors in students' program code. Normal mode implies that the teacher in the classroom computer class is in a standing position behind the student at the computer, moving from one to another. The clearer and more understandable keywords the more easily they are distinguishable. The more rigid and simpler the standard language constructions, the less time is spent helping the student detect and correct errors. This also helps to reduce the strain on the teacher’s visual organs.

Delphi based on Pascal has a very low barrier to entry. A visual environment that supports formatting, syntax highlighting, and debugging features. The environment is ergonomically balanced and comfortable for both beginners and advanced experienced users.

Delphi belongs to the RAD family of tools. Manual input of program text is combined with interactive manipulation of ready-made components. The teacher can vary the methodology, starting with both “pure” programming and “rapid development”. It all depends on the age and psychophysical characteristics of a particular group of students. You can even divide a single lesson into two parts - “classical programming” and interactive training V game form to maintain concentration.

Current version is Delphi XE5, but it supports running in "canonical" mode teaching examples a la console application with text or file input/output.

Delphi XE5 has a built-in set of 3D visual components. Programming truly becomes interactive. This is not “tedious typing of program text”, but live interaction with the development environment. Part of the time can be devoted to “drawing in 3D” in design-time, then you can move on to the programmatic dynamic creation of scene objects in runtime, then added animation effects in design-time, then programmed reactions to user actions.

Delphi is based on traditional Pascal; many examples can be easily transferred to new version XE5. Educational materials on Pascal can also be used in XE5 with very moderate modifications. Any development of training materials is easily feasible based on the existing very extensive base examples and educational literature.

Delphi based on Pascal - language professional development. Millions of lines of code, commercial successful applications, a wide range of application areas. Language capabilities of the modern version of this language Do not limit students to completing educational examples. Generic programming techniques and extended RTTI can be used.

Delphi XE5 allows you to create applications for mobile systems. Now none of the students will feel doubts about the relevance of the technology being studied. Phone or tablet on Android based, iPhone or iPad - these modern iOS and Android devices can be programmed to Delphi language/Pascal.

Delphi provides early employment for youth. Upon graduation, due to simplicity and accessibility, which is the key to obtaining reliable skills in practical use, graduates can independently create practically significant applications, including interaction with a DBMS at the component level.

Delphi facilitates project-based learning in its early stages. An easy-to-learn language, complemented by visual components for quick interface development, built-in capabilities for interacting with databases - all this creates a technological environment that allows you to move from training examples to implementation almost instantly interesting projects.

Delphi contributes to the stabilization of curricula and programs thanks to the ability to conduct multi-platform development for Windows, Mac OS, iOS and Android. If you study a separate language or technology for each platform, you should plan your training in the following areas:

• one semester C;
• one semester C++;
• one semester of Java;
• one semester C#;
• one semester of Objective-C.

Delphi is a universal environment, invariant with respect to the platforms for which the application is created. New software/hardware platforms can be added based on their popularity in the market. The curriculum, number and content of laboratory work remains unchanged, adjusted for consideration of specific features new platform, which within a single tool does not require significant time expenditure.

Delphi for teachers and teachers promotes the universalization of their own knowledge. With the current pace of development of IT technologies, there is a great danger that students may surpass teachers in knowledge. Even if this is only superficial acquaintance, shallow skills, formal methods - there is always a risk of loss of image. With Delphi for Windows, Mac OS, iOS and Android, the teacher feels protected because... the newest and most relevant operating systems and devices are not a problem. Almost any modern and fashionable device brought by students to an educational institution can be programmed based on a single code.

Delphi, as a unified technological environment, promotes collaboration between teachers and students. Working group can be formed from students of any level, graduate students and teachers. The situation of loss of continuity is eliminated when a junior year student is assigned to continue the work of a graduate student, but all the time is spent on mastering a new language (Java or C++), and the actual work on modernizing the algorithmic content of the system is doomed to failure. The unity of language and tools, accessible to everyone, starting from school, is the key to success in creating common base source codes and the ability to move from the level " educational application" to " science project».

Delphi based on Pascal is not a “lifelong” commitment to this particular technology. C++Builder is a visual rapid development environment built on the same principles as Delphi. Students who have mastered Delphi almost instantly adapt to C++Builder and begin to master the specifics and capabilities professional languages C/C++.

C++Builder should be considered as the next step in learning programming technologies after Delphi.

C/C++ are one of the most common programming languages, but they were originally designed for already trained developers with work experience. What is extremely important here is the gradual presentation of the material with maximum elaboration and consolidation of the acquired knowledge using specific examples.

Training examples should be as clear as possible. Abstract problems demotivate students, and the visual environment of C++Builder with ready-made components for rapid development helps maintain interest in performing practical problems.
When using C++Builder as a continuation of work in Delphi, they save time on adapting students to new environment. All emphasis is placed on the syntactic features of C/C++, and not general principles building applications.

Studying and implementing standard algorithms in parallel with familiarization with the C++ programming language significantly increases the workload for students. If the algorithms have already been mastered, and the skills for their implementation have already been developed, then learning C++ is significantly accelerated.

The complexity of C++ syntax is greatly offset if students already know how to independently develop and debug applications. Then Delphi becomes a very convenient and useful environment for acquiring general programming skills, and moving to C++Builder is a way to further improve knowledge. It is possible that this will be implemented in the form of elective classes or additional subjects in specialized classes at school or special elective courses at a university.

The educational and methodological base for working in Delphi is easily portable to C++Builder, preserving most illustrative examples execution of prototypes real applications. Typical method quick dating with C++Builder is to perform already completed tasks in Delph, because the visual components and methods of interacting with databases remain the same.

After learning the basics of programming in Delphi and improving your development skills in C++Builder, you can use HTML5 Builder as part of RAD Studio XE5. HTML5 Builder is a user-friendly visual environment for web development, including HTML5, CSS3, JavaScript and PHP. This approach will allow us to consider a wide range of modern programming technologies for creating applications for Windows, Mac OS, iOS, Android, as well as client and server web applications.

RAD Studio XE5 with Delphi XE5 and C++Builder is a set of environments ideal for teaching programming, which is easily adapted to various educational institutions, their profiles, the level of initial training of students, teaching methods, as well as learning goals and objectives - from initial acquaintance to professional skills.

If training programs involve the use previous versions Delphi and C++Builder, then when you ship RAD Studio XE5 you have access to them, including: Delphi XE4, Delphi XE3, Delphi XE2, Delphi XE, Delphi 2010, Delphi 2009, Delphi 2007, Delphi 7, C++Builder XE4, C++Builder XE3, C++Builder XE2, C++Builder XE, C++Builder 2010, C++Builder 2009, C++Builder 2007, C++Builder 6. This allows you to update curriculum before using XE5 versions without violating the current educational process, gradually updating course content and content practical work up to mobile development for iOS and Android.

Continuity is maintained with RAD Studio XE5 teaching materials, educational literature and educational plans and strategies, which is extremely important, because more than 70% of schools Russian Federation use Delphi/Pascal in training. But more complex programming languages ​​C/C++ are also available as you continue to improve skills and develop knowledge, along with web programming technologies. When creating applications for various platforms, such as Windows, Mac OS, iOS, Android, as well as web applications, curricula become relevant, and students are guaranteed to be in demand as having received a universal education in the field of programming.

IN Delphi section We have collected free video lessons on this programming language. Delphi is an imperative, structured, object-oriented programming language (formerly Object Pascal). Embarcadero Delphi (formerly Borland Delphi and CodeGear Delphi) is an integrated software development environment for Microsoft Windows in Delphi, originally created by Borland and currently owned and developed by Embarcadero Technologies. Learning Delphi from video lessons will be useful for both beginners and more experienced programmers. You can watch video tutorials from the Delphi category online completely free of charge at any convenient time. For some Delphi video lessons you can download additional materials. Happy learning!

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Delphi for beginners. Delphi XE3 programming environment

It talks about the basics of programming in Delphi, training for beginners. In this video tutorial we will get acquainted with the Delphi XE3 development environment, study its interface and create a simple program in it. To get started you need to create new project. This can be done through the File - New menu. As a result, we have an empty form of the future program. Now we can place on this form various buttons, fields for data entry and other components that are included in...

The book is a practical guide to programming in Embarcadero Delphi. It presents technology visual design and event programming, the process of creating VCL applications is discussed in detail, the purpose of basic components is shown, issues of graphics programming, working with databases are considered Microsoft data Access. Attention is paid to the development of Multi-Device applications, including for Android platforms, using FireMonkey components, using FireDAC components to work with integrated databases SQLite data, 3D graphics, Float and Path animation, working with sensors.
For beginner programmers

3D graphics

Graphics space

The starting point for creating a 3D application is the 3D Application template (Fig. 7.1). An application built from this template initially contains a form whose base class is the TForm3D class. The TForm3D class represents a graphics space into which you can place a 3D object, such as a cube, sphere, or cylinder.

Please note that 3D objects can also be used in regular, non-3D applications, but in this case the Viewport3D component must be used as the graphic space.

Animation

Animation is the process of giving objects the ability to change, for example, move, rotate, change color.

Delphi provides the programmer with a set of FireMonkey components (they are located on the Animations tab) that allow you to animate almost any object: geometric figure, illustration, user interface element. Please note that you can animate not only a single object, but also a group of objects, for example, input fields, lists and command buttons located on the panel.

Animating an object is done by animating its properties. For example, to make a rectangle (element of a bar chart) “grow”, you need to animate the Height property. In order for an object, for example, a picture, to start moving, you need to animate the properties that determine the position of the object: Position.X and Position.Y.

Properties of an object that can be animated are marked with a film strip icon (Figure 8.1). The above example shows that objects have many properties that can be animated. These are properties that determine the size of the component (Width, Height), position (Position) and orientation of the component (RotationCenter and RotationAngle), color (Color), degree of opacity (Opacity) and others.

Databases

Delphi provides the programmer with a set of components, using which he can create a program that works with almost any database: from Microsoft Access to Microsoft SQL Server and Oracle.

Events

The appearance of the application form tells you how the program should work. Obviously, the user must select the field (at the beginning of the program, the Price without discount field is active) in which he wants to enter information, and use the keyboard to enter a number. Then he must select another field, for example, Discount, and also enter a number on the keyboard. The program must analyze which of the fields is active and perform the calculation.

In order for the program to work as described, it must process events that occur when fields (areas) for entering information are touched and command buttons are pressed. When the screen is touched, the MouseDown event occurs. It is these events that are processed. Please note that in order for the Label component to perceive events, its HitTest property must be assigned True value(by default, the HitTest property of Label components is False).

Event handling procedures are created in the usual way: first you need to select the component for which you want to create an event handling procedure, then on the Events tab of the Object Inspector window, select the event and double-click the left mouse button in the edit field, which is located to the right of the event name.

Databases in mobile applications

In Multi-Device applications to work with databases, the programmer can use the dbExpress, dbGo and FireDAC components. This chapter is about using FireDAC components. Using the example of the program's operation with the built-in SQLite Expenses database, it demonstrates the purpose and features of using FireDAC components and data binding technology.

IN mobile applications DBMSs are used to store data, which are usually called built-in (embedded - built-in, included, integrated). From an architectural point of view, an embedded DBMS is a common one, although usually with less capabilities than a DBMS built on SQL server. As an embedded DBMS in Multi-Device applications, you can use the IBLite server or the freely distributed SQLite database server.

FireDAC data access components

The core FireDac components are found in the FireDac tab of the Components palette and provide access and manipulation of data. The FDConnection component provides a connection to the database, the FDTable component provides access to tables, and the FDQuery component provides interaction with the database via SQL queries.

Data Display Components

Most often, information in mobile applications is presented in the form of lists or in a combined format. The contents of key fields are usually presented as a list. With a combined method key information is displayed as a list, and to display all, detailed information a form or table is used about the object.

To present information in the form of a list, you can use the ListBox and ListView components. To present information in table form, use the StringGrid component (on the Grids tab).

Creating a Database

A database is a file that contains tables containing information and, as a rule, it is created before starting work on the application using the appropriate DBMS. The SQLite database that will be used during the development phase of the application can be created using FireDac Explorer. The task of creating a working database can be assigned to the database application: when you first launch the program on the device, the application will create the database.

Let's look at the process of creating a SQLite database using an example. Let's create an expenses database using FireDAC Explorer, which is one single table expenses

Let's look at the DelphiXE5 main menu. We won’t go too deep and consider absolutely all the points, but we’ll go over the main features, since when creating applications in the Delphi development environment we will constantly use this menu and its capabilities. Of course, you can use “hot keys”, but in the first stages of programming, it is very important to know where in the menu, what is located and what is responsible for what.

Drawing. Delphi XE5 main menu

The first place to start is with the menu File.

New- creating a new project, form or template. If you hover your mouse over this item, a submenu will open in front of you, in which you can see the main types of forms and modules that will most often be created:

VCL Forms Application - Delphi- creates a new project with standard controls.

VCL Metropolis UI Application

FireMonkey Desktop Application - Delphi- creates a new project with FireMonkey controls

FireMonkey Mobile Application - Delphi

FireMonkey Metropolis UI Application

Package - Delphi

VCL Form - Delphi- adds a new empty standard form to the project

FireMonkey Form - Delphi- adds a new empty FireMonkey form to the project

FireMonkey Mobile Form - Delphi

Unit - Delphi- adds a new module to the project

Other- displays a window with shortcuts for all modules that can be created

Open- open existing file, supported by Delphi.

Open Project- open an existing project. A project can consist of several modules, and this is what needs to be opened in order to work on the program. If you open a module file using the menu File | Open, then the open module will not be a project, and there is no point in compiling it.

Reopen- reopen a project that was recently opened.

Close- close the current module.

CloseAll- close everything.

UseUnit- use the module.

Print- print the module.

Exit- exit.

The term module is used several times in the text. Therefore, it is necessary to explain what it is. Module is a file containing program code or part of code. Most often this is a simple text file with the extension pas. Nowadays, a module is also understood as files containing the visual part of the program. The fact is that although the code and visual part are stored in different files, they are closely related.

Menu Edit contains all the basic commands for editing code and components on the form

Now you shouldn’t look at all the commands in this menu, because they won’t be remembered anyway. When we move on to the practice of programming and start writing our own programs, everything will naturally, gradually, be deposited in our memory.

Search- search and replace a sequence of characters (text) in the source code

Using the menu View you can enable or disable specific panels within the development environment. If you look here you can see large number various menu items. These items are much larger than the panels that are visible to us by default. Now we can only see the main panels.

Menu Refactor. The concept of refactoring can be translated as improvement. IN in this case this is an improvement to existing code. Since at the moment we have not written absolutely any code, we will look at this point a little later.

On the menu Project there are project management functions. Let's look at the main items of this menu:

Add to project- adds an existing file to our project;

Remove from project- removes a module from the project;

Add to repository- add to storage. The module will be added as a template, and windows can be created based on it;

View source- allows you to view the source code of the project. This is not the code of any module, this is the code of the project, where Delphi automatically generates the initialization code for automatically created forms;

Compile “Project name”- compiles the project we created;

Build “Project name”- starts the construction of the project;

Compile All Projects- compiles all open projects;

Build All Projects- building all open projects;

Options- allows you to configure the properties of our project.

What is the difference between compiling and building? When a program is compiled, Delphi creates so-called intermediate files, which will later be used when assembling our project into an executable file. When the next compilation starts, those modules that have not changed will not be compiled, but the previously created intermediate files will be used. When you build a project, everything is compiled. This is necessary when we have made any changes to our project settings and Delphi does not recompile the modules.

In order to quickly compile a project, you can use the keyboard shortcut + . Compilation is very convenient when we want to check our code for various errors.

On the menu Run there are functions for launching an application from the development environment and debugging programs. We don’t have anything to launch yet, so we won’t do anything here for now. Debugging itself deserves a separate discussion. We will review most of the items on this menu as needed.

On the menu Component there are menu items with which you can create new component or install an existing package.

On the menu Tools you can find menu items with which you can configure the Delphi Development Environment itself, as well as many additional utilities.

Help- serves to call help information.