Creating a graphical interface using Qt. Creating applications with a graphical interface How to create a program interface in c
Last update: 26.05.2019
In Xamarin.Forms, the visual interface is made up of pages. The page is an object of class Page , it occupies the entire screen space. That is what we see on the screen mobile device is a page. An application can have one or more pages.
The page accepts one of the layout containers as content, which in turn contains standard visual elements such as buttons and text fields, as well as other layout elements.
Let's take the HelloApp project created in the previous topic (or create a new one). By default, the entire interface is created in the App class, which is located in the App.xaml.cs file and represents the current application:
Its default code is:
Using System; using Xamarin.Forms; using Xamarin.Forms.Xaml; namespace HelloApp ( public partial class App: Application ( public App() ( InitializeComponent(); MainPage = new MainPage(); ) protected override void OnStart() ( // Handle when your app starts ) protected override void OnSleep() ( / / Handle when your app sleeps ) protected override void OnResume() ( // Handle when your app resumes ) ) )
The App class starts with the constructor, where the InitializeComponent() method is first called, which initializes the object, and then the MainPage property is set. Through this property, the App class sets home page applications. In this case, it is defined by the HelloApp.MainPage class, which is the class defined in the MainPage.xaml and MainPage.xaml.cs files.
But given way not the only one. Xamarin.Forms allows you to create a visual interface either using C# code or declaratively using the xaml language, similar to html, or a combination of these approaches.
Creating an interface from C# code
Let's add a regular C# class to the HelloApp project, which we'll call StartPage .
And define the following content in this class:
Using Xamarin.Forms; namespace HelloApp ( class StartPage: ContentPage ( public StartPage() ( Label header = new Label() ( Text = "Hello from Xamarin Forms" ); this.Content = header; ) ) )
This class represents a page, so it inherits from the ContentPage class. The constructor creates a label with text, which is set as the content of the page (this.Content = header).
To designate MainPage as start page, change the App class:
Using Xamarin.Forms; namespace HelloApp ( public partial class App: Application ( public App() ( InitializeComponent(); MainPage = new StartPage(); ) protected override void OnStart() ( // Handle when your app starts ) protected override void OnSleep() ( / / Handle when your app sleeps ) protected override void OnResume() ( // Handle when your app resumes ) ) )
The MainPage property now points to the newly created StartPage.
It's also worth noting that Visual Studio has ready template to add new page classes with the simplest code. So, to add a new page, you need to select the Content Page (C#) template when adding a new element:
This class is added to main project solutions (in this case, HelloApp).
The added page class will have the following code:
Using System; using System.Collections.Generic; using System.Linq; using System.Reflection.Emit; using System.Text; using Xamarin.Forms; namespace HelloApp ( public class Page1: ContentPage ( public Page1() ( Content = new StackLayout ( Children = ( new Label ( Text = "Hello Page" ) ) ); ) ) )
This class will also inherit from the base ContentPage class and will have almost the same organization as the MainPage class created above.
And also in the application class, we can set this page as the start page:
Using Xamarin.Forms; namespace HelloApp ( public partial class App: Application ( public App() ( InitializeComponent(); MainPage = new Page1(); ) //........... ) )
Ministry of Education and Science of the Russian Federation
Federal State Budgetary Educational Institution
higher professional education
"UFA STATE OIL
TECHNICAL UNIVERSITY"
Department of Computer Science and Engineering Cybernetics
Creating a GUI Application in Microsoft Visual Studio 2010
Teaching aid
for laboratory and practical classes
with students of the direction
230100 (09.03.01) "Informatics and Computer Engineering"
The teaching aid provides theoretical information, tasks for practical and laboratory work of the course "Programming".
The manual is addressed to teachers of the discipline, as well as students of the direction: 230100 "Informatics and Computer Engineering".
Compiled by: Gabdullina A.A., Art. lecturer at the department VTIK
Druzhinskaya E.V., Art. lecturer at the department VTIK
Reviewer: Filippov V.N., Ph.D., Associate Professor of the Department. VTIK.
1. Theoretical information 4
1.1. Basic concepts 4
1.2. Introduction to Windows Form Application in Microsoft Visual Studio 2010 4
1.3. Form 7 control
1.5. MessageBox 9 function
1.6. TextBox Control 10
2.Practical task. Introduction to Windows Form Application in Microsoft Visual Studio 2010 12
2.1. Assessment structure for completed work 12
2.2. Procedure for performing practical work 12
3. Laboratory work. Application Development in Microsoft Visual Studio 2010 16
3.1. Lab order 16
3.2. Task 1. Tabulation of a function and calculation of its values in the specified interval with a given step 16
3.3. Individual tasks 19
3.4. Task 2. Processing two-dimensional arrays 21
3.5. Individual tasks 27
Theoretical information
1.1. Basic concepts
Automation of information processes is currently represented, first of all, by the development of a software application with a graphical user interface (GUI) that manages data flows.
Graphical User Interface (GUI) is a system of means for user interaction with a device, based on the presentation of all system objects and functions available to the user in the form of graphical screen components (windows, buttons, scroll bars, etc.).
Most often, the interface elements in the GUI are implemented on the basis of metaphors and display their purpose and properties, which makes it easier for unprepared users to understand and master programs. Thus, the user's work is carried out with screen forms containing control objects and toolbars with action buttons for processing.
A standard graphical user interface must meet a number of requirements:
Maintain the information technology of the user's work with the software product;
Focus on the end user who communicates with the program at the external level of interaction;
Satisfy the “six” principle, when no more than 6 concepts are included in one menu bar, each of which contains no more than 6 options;
maintain a standardized purpose of graphic objects and, if possible, their location on the screen.
In object-oriented programming, we deal with classes and objects. Objects are composite data types: they combine multiple values into a single unit and allow us to write and store those values by name. In other words, an object is an unordered collection of properties, each with a name and a value. The named values contained in an object can be either elementary types, such as numbers or strings, or other objects.
When developing non-console applications, the main concept is the Form.
A form is a container for hosting design environment controls.
Properties - the ability to access information stored in this element.
Methods are a set of actions that an object can perform.
An event is an action recognized by an object (for example, a mouse click, a key press), for which a response can be programmed, i.e. object's response to the event.
Good day! In this tutorial, we will create your first GUI application in MS Visual Studio. It will be a kind of "Hello World" for graphical applications. I will say right away that Windows usage Forms is not the only way for C# programmers to create graphical applications (applications with a graphical user interface), but it's a good place to start learning. And so, we launch Visual Studio.
Launched? Then to business! We go to the main menu and select the item "File - New - Project", as shown in the figure below.
In the window that appears:
- on the left side, select "Templates - Visual C # - Windows";
- in the main area, select the element " Windows application forms";
- in the lower part of the window, enter the name of the project and indicate its location on the disk.
In general, as shown in the figure below.
Did you specify what you need? Then click on the "OK" button. Now you should see something like this (the main areas are highlighted with rectangles):
In the image above, I've labeled the main areas: the designer area (top left), the solution explorer area (top right), and the properties area (bottom right). These are the areas we will work with most often.
In the designer area, there is now an empty “form”, this is the so-called window, in this case, the main window of our program. The properties area displays the properties of the element selected in the designer, in this case, our form, but the solution explorer area contains project files, including those related to the forms (windows) of the program. And now, let's change our form a bit, and run this first application.
To do this, select the form in the designer (for this, you can simply left-click on the form) and go to the properties block, in which we find the line “Text” (the word is text, we are looking for it in the left column), as shown in the figure below.
Property "Text" of the main form of the application
Please note that the left column shows the name (property name), and the right column shows its value.
In this case, we are dealing with a text property, and its value is displayed in the window title, so let's now put something of our own there, for example, something like: "Main window", as shown in the figure below:
Now, you can build the project and run it. To do this, go to the main menu and select "Build - Build Solution". And then we launch the application, for this we select the item "Debug - Run without debugging" in the main menu. As a result, you should see the following window.
In the next lesson, we'll look at simple job with the form designer, and customization of elements GUI, and this lesson has come to an end, we have created the first graphical application, compiled and launched it.
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I have made many different sections of the Nintendo DS GUI system like buttons and textboxes and checkboxes but I need a way to hide these classes in one Gui class so that I can draw everything on the screen all at once and check all the buttons at once so that check if any buttons are pressed. My question is what is the best way to organize all classes (like buttons and textboxes) into a single GUI class?
Here's one way I thought, but it doesn't seem right:
Edit: I am using C++.
Class Gui ( public: void update_all(); void draw_all() const; int add_button(Button *button); // Returns button id void remove_button(int button_id); private: Button *buttons; int num_buttons; )
This code has a few problems, but I just wanted to give you an idea of what I want.
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This question is very similar to the one I was about to post, only mine is for Sony PSP programming.
I've been looking for something for a while, I've consulted some books and VTMs and so far this is a rough idea simple systems ui.
Class uiElement() ( ... virtual void Update() = 0; virtual void Draw() = 0; ... ) class uiButton() public: uiElement ( ... virtual void Update(); virtual void Draw() ; ... ) class uiTextbox() public: uiElement ( ... virtual void Update(); virtual void Draw(); ... ) ... // Other ui Elements class uiWindow() ( ... void Update (); void Draw(); void AddElement(uiElement *Element); void RemoveElement(uiElement *Element); std::list
princple is the creation of the window and the attact elements user interface to it, and call the draw and update methods from the corresponding main functions.
Nothing works for me yet, as I'm having problems with the drawing code. With various APIs on PC and PSP, I'm looking at wrapper code for OpenGL and psp gu.
Hope this helps.
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One useful strategy to keep in mind could be the composite pattern . At a low level, it can allow you to more easily handle all GUI objects (and collections of objects) once they've been created. But I don't know anything related to GUI design, so one place to find general inspiration is in the source code of an existing project. WxWidgets is a cross-platform GUI with an accessible source code. Good luck with your project!
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For those interested, here is my open source, BSD-licensed GUI toolkit for the DS:
Subject2k's answer is pretty good, but I would seriously recommend having code that contains child interface elements in the uiElement base class. This is the pattern I followed in Woopsie.
If you not support this in the base class, you will run into serious problems when trying to implement anything more complex than a text box and a button. For instance:
- Table panels can be modeled as several buttons grouped into a single parent element a user interface that provides mutual exclusivity of choice;
- Groups of radios (over time);
- Scrollbars can be represented as a slider/gutter element and an up/down button;
- Scroll lists can be represented as a container and several user interface elements.
Also, it's worth remembering that the DS has a 66 MHz processor and 4 MB of RAM, which is used both to store your program and to execute it (DS disks are loaded into RAM before they run). You really should consider it as an embedded system, which means there is no STL. I removed the STL from Woopsi and managed to save 0.5MB. Not much by desktop standards, but it's 1/8 of the total available DS memory consumed by STL garbage.
I detail the whole process of writing a user interface on my blog:
It includes a description of two algorithms I came up with for screen redrawing, which is the tricky part of creating a GUI (one just breaks rectangles up and remembers visible areas, and the other uses BSP trees, which is much more efficient and easier to understand), optimization tips, etc. d.
In this article, we will talk about creating simple applications using forms in C ++. I want to make it clear right away: the development of "form" C ++ applications will be carried out in the Microsoft Visual Studio environment (we will bypass the main competitor from Borland Software). It is worth noting that in Visual Studio there are two ways to make an application with forms, the decision is made at the time of creating a new project.
The first of these is to use Windows Forms, which implements a graphical user interface and is part of the Microsoft.NET Framework. This approach simplifies access to interface elements. Microsoft Windows by wrapping the Win32 API in managed code. If you put your thoughts in a more understandable form, then this approach is very similar to building a console application, but a little more complicated. uses forms.
The second method is based on using Microsoft Foundation Classes (MFC), a library that takes care of building the application framework. Unlike the first, MFC out of the box uses the MVC (Model-View-Cont roller) pattern. This approach is more complicated than the first, but relying on it, you can easily create a framework for a very interesting applications, eg, text editor or use the Ribbon component and make a menu like in the notorious MS Office 2010.
Creating an application in MS Visual Studio
Let's create a new application: File->New->Project. In the window that appears, as in the figure above, find and select Windows Forms Application, then specify the name (app1) and location of the new project and confirm its creation by clicking the "OK" button.
Before proceeding directly to programming, you should understand what an event is. An event is an action that occurs under certain conditions. The simplest (and most common and) can be considered Load, Click ... let's look at some of them in more detail:
- Activated - an event that occurs when the element is activated.
- Click - occurs when the element is clicked once.
- DoubleClick - double click on the element.
- HelpRequested - fired when a key is pressed
. - Paint - fired when an element is being redrawn.
- MouseLeave - The event fires when the cursor leaves the bounds of the element.
Do not forget that the events specific to an element depend on its type. To view all events available for the form object, select it and select the lightning bolt icon in the properties window. Below is a part of the events for the elementForm1. As you can see, the Form1_Load function is selected for the Load event, so the code contained in this function will be called when the form is loaded.
Open the file Form1.h, there will be the following code:
Private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^ e)( )
This is the same Form1_Load function that fires when the form is loaded. Let's verify this by adding a TextBox component to the form.
To do this, open the form resource and select it. Next, select the Toolbox toolbar and drag the TextBox component onto the form. Modify the Form1_Load function as follows:
Private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^ e) ( textBox1->Text = "Hello, World!"; //textBox1 is the name of the text box you added)
Run the project, as a result, the following message should appear:
That's all for now, continued in the following lessons.
