java 应用程序 gui_用于构建简单GUI应用程序的示例Java代码

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java 应用程序 gui

A GUI -- [Graphical User Interface][] -- of an application built using [Java][] is made up of layers of containers. The first layer is the window used to move the application around the screen of your computer. It is a top-level container that gives all other containers and graphical components a place to work in. For a desktop application, this top-level container is usually made using the JFrame class.

使用[Java][]构建的应用程序的GUI( [图形用户界面][Graphical User Interface] )由多个容器层组成。 第一层是用于在计算机屏幕上移动应用程序的窗口。 它是一个顶级容器，为所有其他容器和图形组件提供了工作的场所。对于桌面应用程序，通常使用JFrame类来制作此顶级容器。

## 背景 **(** Background **)** ##

How many layers a GUI has depends on your design. You can place graphical components such as text boxes, labels, and buttons directly into the [JFrame][], or they can be grouped in other containers depending on how complex the application GUI needs to be.

GUI的层数取决于您的设计。 您可以将诸如文本框，标签和按钮之类的图形组件直接放置到[JFrame中][JFrame] ，也可以将它们组合在其他容器中，具体取决于应用程序GUI的复杂程度。

This sample code below shows how to build an application out of a JFrame, two JPanels and a JButton, which determines the visibility of the components held in the two JPanels. Follow along with what is happening in the code by reading the [implementation comments][], indicated by two slashes at the beginning of each comment line.

下面的示例代码显示了如何使用JFrame，两个JPanel和一个JButton构建应用程序，该应用程序确定两个JPanel中包含的组件的可见性。 通过阅读[实现注释][implementation comments] ，跟踪代码中发生的一切，在每个注释行的开头用两个斜杠表示。

This code goes with the [Coding a Simple Graphical User Interface - Part I][] step-by-step guide. It shows how to build an application out of a `JFrame`, two `JPanels` and `JButton`. The button determines the visibility of the components held within the two `JPanels`.

该代码与“ [编码简单图形用户界面-第一部分”][Coding a Simple Graphical User Interface - Part I]逐步指南一起使用。 它显示了如何使用`JFrame` ，两个`JPanels`和`JButton`来构建应用程序。 该按钮确定两个`JPanels`包含的组件的可见性。

## Java代码 **(** Java Code **)** ##

![Business team at computer][]

Comstock/Stockbyte/Getty Images Comstock / Stockbyte / Getty图片

Compare this Java code with program listing generated from the [Coding a Simple Graphical User Interface - Part II][] which uses the NetBeans GUI Builder to create the same [GUI][] application.

将此Java代码与“ [编码简单图形用户界面-第二部分”][Coding a Simple Graphical User Interface - Part II]生成的程序清单进行比较，该[部分][Coding a Simple Graphical User Interface - Part II]使用NetBeans GUI Builder创建相同的[GUI][]应用程序。

//Imports are listed in full to show what's being used
    //could just import javax.swing.* and java.awt.* etc..
    import javax.swing.JFrame;
    import javax.swing.JPanel;
    import javax.swing.JComboBox;
    import javax.swing.JButton;
    import javax.swing.JLabel;
    import javax.swing.JList;
    import java.awt.BorderLayout;
    import java.awt.event.ActionListener;
    import java.awt.event.ActionEvent;
    public class GuiApp1 {
    //Note: Typically the main method will be in a
    //separate class. As this is a simple one class
    //example it's all in the one class.
    public static void main(String[] args) {
    new GuiApp1();
    }
    public GuiApp1()
    {
    JFrame guiFrame = new JFrame();
    //make sure the program exits when the frame closes
    guiFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    guiFrame.setTitle("Example GUI");
    guiFrame.setSize(300,250);
    //This will center the JFrame in the middle of the screen
    guiFrame.setLocationRelativeTo(null);
    //Options for the JComboBox
    String[] fruitOptions = {"Apple", "Apricot", "Banana"
    ,"Cherry", "Date", "Kiwi", "Orange", "Pear", "Strawberry"};
    //Options for the JList
    String[] vegOptions = {"Asparagus", "Beans", "Broccoli", "Cabbage"
    , "Carrot", "Celery", "Cucumber", "Leek", "Mushroom"
    , "Pepper", "Radish", "Shallot", "Spinach", "Swede"
    , "Turnip"};
    //The first JPanel contains a JLabel and JCombobox
    final JPanel comboPanel = new JPanel();
    JLabel comboLbl = new JLabel("Fruits:");
    JComboBox fruits = new JComboBox(fruitOptions);
    comboPanel.add(comboLbl);
    comboPanel.add(fruits);
    //Create the second JPanel. Add a JLabel and JList and
    //make use the JPanel is not visible.
    final JPanel listPanel = new JPanel();
    listPanel.setVisible(false);
    JLabel listLbl = new JLabel("Vegetables:");
    JList vegs = new JList(vegOptions);
    vegs.setLayoutOrientation(JList.HORIZONTAL_WRAP);
    listPanel.add(listLbl);
    listPanel.add(vegs);
    JButton vegFruitBut = new JButton( "Fruit or Veg");
    //The ActionListener class is used to handle the
    //event that happens when the user clicks the button.
    //As there is not a lot that needs to happen we can
    //define an anonymous inner class to make the code simpler.
    vegFruitBut.addActionListener(new ActionListener()
    {
    @Override
    public void actionPerformed(ActionEvent event)
    {
    //When the fruit of veg button is pressed
    //the setVisible value of the listPanel and
    //comboPanel is switched from true to
    //value or vice versa.
    listPanel.setVisible(!listPanel.isVisible());
    comboPanel.setVisible(!comboPanel.isVisible());
    }
    });
    //The JFrame uses the BorderLayout layout manager.
    //Put the two JPanels and JButton in different areas.
    guiFrame.add(comboPanel, BorderLayout.NORTH);
    guiFrame.add(listPanel, BorderLayout.CENTER);
    guiFrame.add(vegFruitBut,BorderLayout.SOUTH);
    //make sure the JFrame is visible
    guiFrame.setVisible(true);
    }
    }

> 翻译自: [https://www.thoughtco.com/example-java-code-for-building-a-simple-gui-application-2034066][https_www.thoughtco.com_example-java-code-for-building-a-simple-gui-application-2034066]

java 应用程序 gui

[Graphical User Interface]: https://www.thoughtco.com/benefits-of-graphical-user-interface-1206357
[Java]: https://www.thoughtco.com/what-is-java-2034117
[JFrame]: https://www.thoughtco.com/create-a-simple-window-using-jframe-2034069
[implementation comments]: https://www.thoughtco.com/java-comments-using-implementation-comments-2034198
[Coding a Simple Graphical User Interface - Part I]: https://www.thoughtco.com/coding-a-simple-graphical-user-interface-2034064
[Business team at computer]: /images/20221123/67e94dd4121e4fe5920d5f07d994da9a.png
[Coding a Simple Graphical User Interface - Part II]: https://www.thoughtco.com/what-is-javafx-2034192
[GUI]: https://www.thoughtco.com/gui-2034108
[https_www.thoughtco.com_example-java-code-for-building-a-simple-gui-application-2034066]: https://www.thoughtco.com/example-java-code-for-building-a-simple-gui-application-2034066