java - 在 JCombBox 中进行选择时如何使 JLabel 更改图像-6ren

java - 在 JCombBox 中进行选择时如何使 JLabel 更改图像

转载作者：搜寻专家更新时间：2023-11-01 01:44:48

每次用户在 JComboBox 中选择一个选项时，我都想让我的 JLabel 发生变化，它从文本文件中获取值，请真的需要帮助....

import javax.swing.*;
import javax.swing.border.*;
import java.util.*;
import java.util.List;
import java.io.IOException;
import java.util.Scanner;
import java.io.*;
import java.awt.*;
import java.awt.event.*; 
import java.net.*;
import java.applet.*;

public class MusicOnWeb extends JApplet {
    JPanel P = new JPanel();

    JLabel Title = new JLabel();
        JLabel Logo = new JLabel();
            JLabel Category = new JLabel();
            JLabel List = new JLabel();
            JLabel Image = new JLabel();
            JSeparator jSeparator1 = new JSeparator();
            JSeparator jSeparator2 = new JSeparator();
            JSeparator jSeparator3 = new JSeparator();
            JSeparator jSeparator4 = new JSeparator();
            JSeparator jSeparator5 = new JSeparator();
            JButton Cc = new JButton();
            JButton Pp = new JButton();
            JButton Jz = new JButton();
            JButton Wn = new JButton();
            JButton Cart = new JButton();
            JComboBox Combo1 = new JComboBox();
            JComboBox Combo2 = new JComboBox();
            JComboBox Combo3 = new JComboBox();
            JComboBox Combo4 = new JComboBox();

        Font f = new Font("Lucida Calligraphy", Font.BOLD,25);

    final java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("MMMM dd yyyy GGG hh:mm:ss aaa"); 
    JLabel TimeLabel = new JLabel();

     ActionListener al = new ActionListener() {  
        public void actionPerformed(ActionEvent ae) {  
                    TimeLabel.setText(sdf.format(new java.util.Date())); 
            }  
        };

    String[] CB1 = new String[5];
    String[] CB2 = new String[5];
    String[] CB3 = new String[5];
    String[] CB4 = new String[5];

    String Music [ ] = {" Seal.jpg"};

    GridBagConstraints gbc;

public void init() {
        P.setBackground(new Color(102, 102, 102));
        P.setBorder(javax.swing.BorderFactory.createCompoundBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, new java.awt.Color(255, 0, 51), new java.awt.Color(0, 153, 255), new java.awt.Color(0, 204, 153), new java.awt.Color(0, 204, 102)), javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0), 3)));
        P.setLayout(new GridBagLayout());

 try {
    File F= new File("Classics.txt");
    Scanner inFile = new Scanner(new FileReader(F)).useDelimiter("\\' '| \r");
    int i=0;
    while (inFile.hasNextLine()){
    CB1[i] = inFile.nextLine();
    i++;
}} catch (Exception e) {

    }

 try {
    File F= new File("Western.txt");
    Scanner inFile = new Scanner(new FileReader(F)).useDelimiter("\\' '| \r");
    int i=0;
    while (inFile.hasNextLine()){
    CB2[i] = inFile.nextLine();
    i++;
}}catch (Exception e)  {

    }

 try {
    File F= new File("Pop.txt");
    Scanner inFile = new Scanner(new FileReader(F)).useDelimiter("\\' '| \r");
    int i=0;
    while (inFile.hasNextLine()){
    CB4[i] = inFile.nextLine();
    i++;
}}catch (Exception e)  {

    }

 try {
    File F= new File("Jazz.txt");
    Scanner inFile = new Scanner(new FileReader(F)).useDelimiter("\\' '| \r");
    int i=0;
    while (inFile.hasNextLine()){
    CB3[i] = inFile.nextLine();
    i++;
}}catch (Exception e)  {

    }

        Title.setFont(new Font("Lucida Calligraphy", 1, 27)); 
        Title.setForeground(new Color(102, 102, 255));
        Title.setHorizontalAlignment(SwingConstants.CENTER);
        Title.setText("<HTML><center><b><u>MusicOnWeb</u></b><BR>An Online Music Store</HTML>");
        Title.setBorder(javax.swing.BorderFactory.createLineBorder(new Color(0, 0, 0)));
        gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 0;
        gbc.gridwidth = 10;
        gbc.ipadx = 440;    // To resize components
        gbc.ipady = 25;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(26, 45, 0, 0);     // To move components
        P.add(Title, gbc);

        Logo.setIcon(new ImageIcon("C:\\Users\\Kwasi Addai\\Documents\\Java Work\\Project 1\\Logo.jpg"));
        Logo.setBorder(javax.swing.BorderFactory.createLineBorder(new Color(0, 0, 0)));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.ipadx = -52;
        gbc.ipady = -23;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(26, 46, 0, 0);
        P.add(Logo, gbc);

        Category.setFont(new Font("Kristen ITC", 1, 24)); 
        Category.setHorizontalAlignment(SwingConstants.CENTER);
        Category.setText("Select the Category");
        Category.setBorder(javax.swing.BorderFactory.createEtchedBorder(javax.swing.border.EtchedBorder.RAISED, new Color(102, 204, 255), java.awt.Color.red));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 2;
        gbc.gridwidth = 3;
        gbc.ipadx = 30;
        gbc.ipady = 13;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(18, 46, 0, 0);
        P.add(Category, gbc);

        List.setFont(new Font("Britannic Bold", 0, 27)); 
        List.setHorizontalAlignment(SwingConstants.CENTER);
        List.setText("List of CD's Available");
        List.setBorder(javax.swing.BorderFactory.createEtchedBorder(java.awt.Color.black, java.awt.Color.white));
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 2;
        gbc.gridwidth = 16;
        gbc.gridheight = 2;
        gbc.ipadx = 248;
        gbc.ipady = 22;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(23, 17, 0, 0);
        P.add(List, gbc);

        Image.setBorder(javax.swing.BorderFactory.createLineBorder(new Color(0, 0, 0), 3));
        Image.setMaximumSize(new Dimension(300, 300));
        Image.setMinimumSize(new Dimension(300, 300));
        gbc = new GridBagConstraints();
        gbc.gridx = 9;
        gbc.gridy = 5;
        gbc.gridwidth = 12;
        gbc.gridheight = 9;
        gbc.ipadx = -12;
        gbc.ipady = -12;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(8, 40, 0, 0);
        P.add(Image, gbc);

        TimeLabel.setText("timeLabel");
        TimeLabel.setFont(f);
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 16;
        gbc.gridwidth = 0;
        gbc.ipadx = 278;
        gbc.ipady = 33;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(15, 40, 0, 0);
        P.add(TimeLabel, gbc);
    new javax.swing.Timer(1000,al).start();  

        jSeparator1.setForeground(new Color(102, 102, 102));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 1;
        gbc.gridwidth = 23;
        gbc.ipadx = 958;
        gbc.ipady = 3;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(20, 15, 0, 16);
        P.add(jSeparator1, gbc);

        jSeparator2.setBackground(new Color(0, 0, 0));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 4;
        gbc.gridwidth = 4;
        gbc.ipadx = 340;
        gbc.ipady = 2;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(9, 15, 0, 0);
        P.add(jSeparator2, gbc);

        jSeparator3.setOrientation(SwingConstants.VERTICAL);
        gbc = new GridBagConstraints();
        gbc.gridx = 4;
        gbc.gridy = 2;
        gbc.gridheight = 13;
        gbc.ipadx = 11;
        gbc.ipady = 450;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(-2, 1, 0, 0);
        P.add(jSeparator3, gbc);

        jSeparator4.setBackground(new Color(0, 0, 0));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 15;
        gbc.gridwidth = 23;
        gbc.ipadx = 958;
        gbc.ipady = 1;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(0, 15, 0, 16);
        P.add(jSeparator4, gbc);

        jSeparator5.setOrientation(SwingConstants.VERTICAL);
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 16;
        gbc.gridheight = 3;
        gbc.ipadx = 11;
        gbc.ipady = 95;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(0, 180, 10, 0);
        P.add(jSeparator5, gbc);

        Cc.setFont(new Font("Tahoma", 3, 20)); 
        Cc.setForeground(new Color(0, 0, 102));
        Cc.setText("Classic");
        Cc.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 4, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 5;
        gbc.gridwidth = 2;
        gbc.gridheight = 2;
        gbc.ipadx = 161;
        gbc.ipady = 17;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(29, 65, 0, 0);
        Cc.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Combo1.setModel(new DefaultComboBoxModel(CB1));
                Combo2.setModel(new DefaultComboBoxModel(CB1));
                Combo3.setModel(new DefaultComboBoxModel(CB1));
                Combo4.setModel(new DefaultComboBoxModel(CB1));
                Combo1.setSelectedIndex(0);
                Combo2.setSelectedIndex(0);
                Combo3.setSelectedIndex(0);
                Combo4.setSelectedIndex(0);
            }
        });
         P.add(Cc, gbc);

        Pp.setFont(new Font("Tahoma", 3, 20)); 
        Pp.setForeground(new Color(0, 204, 204));
        Pp.setText("Pop");
        Pp.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 4, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 9;
        gbc.gridwidth = 2;
        gbc.ipadx = 191;
        gbc.ipady = 17;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(16, 65, 0, 0);
        Pp.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Combo1.setModel(new DefaultComboBoxModel(CB4));
                Combo2.setModel(new DefaultComboBoxModel(CB4));
                Combo3.setModel(new DefaultComboBoxModel(CB4));
                Combo4.setModel(new DefaultComboBoxModel(CB4));
                Combo1.setSelectedIndex(0);
                Combo2.setSelectedIndex(0);
                Combo3.setSelectedIndex(0);
                Combo4.setSelectedIndex(0);
            }
        });
        P.add(Pp, gbc);

        Jz.setFont(new Font("Tahoma", 3, 20)); 
        Jz.setForeground(new Color(0, 51, 153));
        Jz.setText("Jazz");
        Jz.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 4, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 11;
        gbc.gridwidth = 2;
        gbc.ipadx = 185;
        gbc.ipady = 17;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(12, 65, 0, 0);
          Jz.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Combo1.setModel(new DefaultComboBoxModel(CB3));
                Combo2.setModel(new DefaultComboBoxModel(CB3));
                Combo3.setModel(new DefaultComboBoxModel(CB3));
                Combo4.setModel(new DefaultComboBoxModel(CB3));
                Combo1.setSelectedIndex(0);
                Combo2.setSelectedIndex(0);
                Combo3.setSelectedIndex(0);
                Combo4.setSelectedIndex(0);
            }
        });
        P.add(Jz, gbc);

        Wn.setFont(new Font("Tahoma", 3, 20)); 
        Wn.setForeground(new Color(0, 102, 102));
        Wn.setText("Western");
        Wn.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 4, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 7;
        gbc.gridwidth = 2;
        gbc.ipadx = 145;
        gbc.ipady = 17;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(18, 65, 0, 0);
          Wn.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Combo1.setModel(new DefaultComboBoxModel(CB2));
                Combo2.setModel(new DefaultComboBoxModel(CB2));
                Combo3.setModel(new DefaultComboBoxModel(CB2));
                Combo4.setModel(new DefaultComboBoxModel(CB2));
                Combo1.setSelectedIndex(0);
                Combo2.setSelectedIndex(0);
                Combo3.setSelectedIndex(0);
                Combo4.setSelectedIndex(0);
            }
        });

        P.add(Wn, gbc);

        Cart.setFont(new Font("Wide Latin", 1, 24)); 
        Cart.setText("Add to Cart");
        Cart.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 5, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 7;
        gbc.gridy = 16;
        gbc.gridwidth = 3;
        gbc.gridheight = 2;
        gbc.ipadx = 53;
        gbc.ipady = 14;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(26, 75, 0, 0);
    Cart.addActionListener(new ActionListener() {
              @Override
    public void actionPerformed(ActionEvent evt) {
    AppletContext ac = getAppletContext();
    URL url = getCodeBase(); // get url of this applet

    try {
    ac.showDocument(new URL(url+"Shopping_Cart.html"));
    } catch(MalformedURLException e) 
    {
        showStatus("URL not found");

        }
    }});
        P.add(Cart, gbc);

        Combo1.setBorder(javax.swing.BorderFactory.createMatteBorder(5, 5, 5, 5, new Color(0, 102, 204)));
        Combo1.setPrototypeDisplayValue("XXXXXXXXXXXX");
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 5;
        gbc.gridwidth = 0;
        gbc.ipadx = 103;
        gbc.ipady = 28;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(23, 17, 0, 0);

        P.add(Combo1, gbc);

        Combo2.setBorder(javax.swing.BorderFactory.createMatteBorder(5, 5, 5, 5, new Color(0, 204, 204)));
        Combo2.setPrototypeDisplayValue("XXXXXXXXXXXX");
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 7;
        gbc.gridwidth = 2;
        gbc.gridheight = 2;
        gbc.ipadx = 103;
        gbc.ipady = 28;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(16, 17, 0, 0);
        P.add(Combo2, gbc);

        Combo3.setBorder(javax.swing.BorderFactory.createMatteBorder(5, 5, 5, 5, new Color(0, 153, 153)));
        Combo3.setPrototypeDisplayValue("XXXXXXXXXXXX");
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 9;
        gbc.gridwidth = 2;
        gbc.gridheight = 2;
        gbc.ipadx = 103;
        gbc.ipady = 28;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(18, 17, 0, 0);
        P.add(Combo3, gbc);

        Combo4.setBorder(javax.swing.BorderFactory.createMatteBorder(5, 5, 5, 5, new Color(0, 0, 204)));
        Combo4.setPrototypeDisplayValue("XXXXXXXXXXXX");
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 11;
        gbc.gridwidth = 2;
        gbc.gridheight = 2;
        gbc.ipadx = 103;
        gbc.ipady = 28;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(18, 17, 0, 0);
        P.add(Combo4, gbc);

       GroupLayout layout = new GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addComponent(P, GroupLayout.PREFERRED_SIZE, 970, GroupLayout.PREFERRED_SIZE)
                .addContainerGap()));
        layout.setVerticalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addComponent(P, GroupLayout.PREFERRED_SIZE, 700, GroupLayout.PREFERRED_SIZE)
                .addGap(0, 68, Short.MAX_VALUE)));
      }
}

最佳答案

基本概念很简单。

我倾向于使用 ItemListener 因为它对不同类型的选择输入比 ActionListener 更敏感

public class TestComboBox05 {

    public static void main(String[] args) {
        new TestComboBox05();
    }

    public TestComboBox05() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new GridBagLayout());
            final JLabel lbl = new JLabel();
            add(lbl);
            JComboBox cb = new JComboBox();

            cb.addItemListener(new ItemListener() {
                @Override
                public void itemStateChanged(ItemEvent e) {
                    if (e.getStateChange() == ItemEvent.SELECTED) {
                        lbl.setText(e.getItem().toString());
                    }
                }
            });

            cb.addItem("1");
            cb.addItem("2");
            cb.addItem("3");
            cb.addItem("4");
            cb.addItem("5");
            add(cb);

        }

    }

}

基本上，当 itemStateChanged 事件被触发时，您需要找到所选项目并相应地更改标签的图标。此示例显示更改文本，但概念是相同的。

关于java - 在 JCombBox 中进行选择时如何使 JLabel 更改图像，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14529011/

文章推荐： java - 带注释的 Collection 袋

文章推荐： javascript - 为什么 typeof 1===1 返回 false 而不是 bool 值

文章推荐： javascript - window.location 在 Chrome 浏览器上不起作用

java - Java 方法如何检索属于该特定方法的方法对象？ ( java )
我正在编写一个具有以下签名的 Java 方法。 void Logger(Method method, Object[] args); 如果一个方法(例如 ABC() )调用此方法 Logger，它应该
java - (Java) Java 找不到我的图像文件
我是 Java 新手。我的问题是我的 Java 程序找不到我试图用作的图像文件一个 JButton。 (目前这段代码什么也没做，因为我只是得到了想要的外观第一的)。这是我的主课代码: packag
java - java Java 有手动垃圾回收吗？
好的，今天我在接受采访，我已经编写 Java 代码多年了。采访中说“Java 垃圾收集是一个棘手的问题，我有几个 friend 一直在努力弄清楚。你在这方面做得怎么样？”。她是想骗我吗？还是我的一生都
java - Java 之谜 - Java
我的 friend 给了我一个谜语让我解开。它是这样的: There are 100 people. Each one of them, in his turn, does the following
java - Java 字节码是否兼容不同版本的 Java？
如果我将使用 Java 5 代码的应用程序编译成字节码，生成的 .class 文件是否能够在 Java 1.4 下运行？如果后者可以工作并且我正在尝试在我的 Java 1.4 应用程序中使用 Jav
java - Java 缺少无符号原始类型是 Java 平台的特征还是 Java 语言的特征？
有关于why Java doesn't support unsigned types的问题以及一些关于处理无符号类型的问题。我做了一些搜索，似乎 Scala 也不支持无符号数据类型。限制是Java和S
java - Java 7 的 Java 字节码可以在其他版本的 Java 中工作吗
我只是想知道在一个 java 版本中生成的字节码是否可以在其他 java 版本上运行最佳答案通常，字节码无需修改即可在较新版本的 Java 上运行。它不会在旧版本上运行，除非您使用特殊参数 (
java -cp 。 test.java 与 java test.java
我有一个关于在命令提示符下执行 java 程序的基本问题。在某些机器上我们需要指定 -cp 。 (类路径)同时执行java程序 (test为java文件名与.class文件存在于同一目录下) jav
java - 使用 Java (Java EE/Java SE) 的数据库应用程序设计模式
我已经阅读 StackOverflow 有一段时间了，现在我才鼓起勇气提出问题。我今年 20 岁，目前在我的家乡(罗马尼亚克卢日-纳波卡)就读 IT 大学。足以介绍:D。基本上，我有一家提供簿记应用
java - Java 中的解析可在 Java 中访问
我有 public JSONObject parseXML(String xml) { JSONObject jsonObject = XML.toJSONObject(xml); r
java - Java 中的解释性语言以及对 Java 方法的调用
我已经在 Java 中实现了带有动态类型的简单解释语言。不幸的是我遇到了以下问题。测试时如下代码: def main() { def ks = Map[[1, 2]].keySet()
java - java 序数 - Java I 类
一直提示输入 1 到 10 的数字 - 结果应将 st、rd、th 和 nd 添加到数字中。编写一个程序，提示用户输入 1 到 10 之间的任意整数，然后以序数形式显示该整数并附加后缀。 public
java - 如何从 Java 执行 Java？
我有这个 DownloadFile.java 并按预期下载该文件: import java.io.*; import java.net.URL; public class DownloadFile {
java - 延迟不适用于 java gui(java)
我想在 GUI 上添加延迟。我放置了 2 个 for 循环，然后重新绘制了一个标签，但这 2 个 for 循环一个接一个地执行，并且标签被重新绘制到最后一个。我能做什么？ for(int i=0;
java - Java 类中的硬编码 Java 列表
我正在对对象 Student 的列表项进行一些测试，但是我更喜欢在 java 类对象中创建硬编码列表，然后从那里提取数据，而不是连接到数据库并在结果集中选择记录。然而，自从我这样做以来已经很长时间了，
java - java 幕后对象创建(java 对象实例化)
我知道对象创建分为三个部分: 声明实例化初始化 classA{} classB extends classA{} classA obj = new classB(1,1); 实例化它必须使用
java - 车辆跟踪系统[java/Java EE]
我有兴趣使用 GPRS 构建车辆跟踪系统。但是，我有一些问题要问以前做过此操作的人: GPRS 是最好的技术吗？人们意识到任何问题吗？我计划使用 Java/Java EE - 有更好的技术吗？如果
java - 逆数组(Java)//逆数组(Java)
我可以通过递归方法反转数组，例如:数组={1,2,3,4,5} 数组结果={5,4,3,2,1}但我的结果是相同的数组，我不知道为什么，请帮助我。 public class Recursion { p
java - Java/Java EE 的构建和集成环境
有这样的标准方式吗？包括 Java源代码-测试代码- Ant 或 Maven联合单元持续集成(可能是巡航控制)ClearCase 版本控制工具部署到应用服务器最后我希望有一个自动构建和集成环境。
java - 我将如何从 java 程序打印文本？ ( java )
我什至不知道这是否可能，我非常怀疑它是否可能，但如果可以，您能告诉我怎么做吗？我只是想知道如何从打印机打印一些文本。有什么想法吗？最佳答案这里有更简单的事情。 import javax.swin

搜寻专家

个人简介

我是一名优秀的程序员,十分优秀！

作者热门文章

滴滴打车优惠券免费领取

全站热门文章

首页

博学

6Ren·AI

商城

java - 在 JCombBox 中进行选择时如何使 JLabel 更改图像