Swing GUI

一、编写HelloWorld

  private static void createAndShowGUI() {
    
    
        // 确保一个漂亮的外观风格
        JFrame.setDefaultLookAndFeelDecorated(true);
        // 创建及设置窗口
        JFrame frame = new JFrame("Swing"); //窗口名称
        frame.setSize(200, 100);  //窗口大小
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  //窗口关闭，退出程序

        // 添加 "Hello World" 内容
        JLabel label = new JLabel("Hello World");
        frame.getContentPane().add(label);

        // 显示窗口
        //frame.pack();   //该句控制窗口自适应输入的内容，修改设置的窗口大小
        frame.setVisible(true);  //显示
    }

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

二、控件

public static void main(String[] args) {
    
    
        // 确保一个漂亮的外观风格
        JFrame.setDefaultLookAndFeelDecorated(true);
        // 创建 JFrame 实例
        JFrame frame = new JFrame("Login Example");
        frame.setSize(750, 1000);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        /* 创建面板，这个类似于 HTML 的 div 标签
         * 我们可以创建多个面板并在 JFrame 中指定位置
         * 面板中我们可以添加文本字段，按钮及其他组件。
         */
        JPanel panel = new JPanel();
        // 添加面板
        frame.add(panel);
        /*
         * 调用用户定义的方法并添加组件到面板
         */
        placeComponents(panel);

        // 设置界面可见
        frame.setVisible(true);
    }

    private static void placeComponents(JPanel panel) {
    
    
        String[] data = {
    
    "one", "two", "three", "four"};
        panel.setLayout(null);

        // 创建 JLabel
        JLabel userLabel = new JLabel("User:");
        /* 这个方法定义了组件的位置。
         * setBounds(x, y, width, height)
         * x 和 y 指定左上角的新位置，由 width 和 height 指定新的大小。
         */
        userLabel.setBounds(10,20,80,25);
        panel.add(userLabel);

        //创建文本域用于用户输入
        JTextField userText = new JTextField(20);
        userText.setBounds(100,20,165,25);
        panel.add(userText);

        // 输入密码的文本域
        JLabel passwordLabel = new JLabel("Password:");
        passwordLabel.setBounds(400,20,80,25);
        panel.add(passwordLabel);

        /*
         *这个类似用于输入的文本域
         * 但是输入的信息会以点号代替，用于包含密码的安全性
         */
        JPasswordField passwordText = new JPasswordField(20);
        passwordText.setBounds(500,20,165,25);
        panel.add(passwordText);

        // 输入富文本域
        JLabel kinderLabel = new JLabel("textArea:");
        kinderLabel.setBounds(10,70,80,25);
        panel.add(kinderLabel);

        // 富文本域
        JTextArea textArea = new JTextArea();
        textArea.setBounds(100,70,550,100);
        panel.add(textArea);

        // 图形化的组件JRadioButton
        JRadioButton radioButton = new JRadioButton("radio");
        radioButton.setBounds(10, 200, 80, 25);
        panel.add(radioButton);
        // 创建登录按钮
        JButton loginButton = new JButton("login");
        loginButton.setBounds(120, 200, 80, 25);
        panel.add(loginButton);

        //图形化的组件JCheckBox
        JCheckBox checkBox = new JCheckBox("check");
        checkBox.setBounds(300, 200, 80, 25);
        panel.add(checkBox);

        //下拉框
        JComboBox jComboBox = new JComboBox(data);
        jComboBox.setBounds(450, 200, 200, 30);
        panel.add(jComboBox);


        JColorChooser colorChooser = new JColorChooser(Color.CYAN);
        colorChooser.setBounds(10, 250, 600, 200);
        panel.add(colorChooser);


        JList<String> jList = new JList<>(data);
        jList.setBounds(10, 500, 600, 100);
        panel.add(jList);

        JScrollBar jScrollBar = new JScrollBar(1);
        jScrollBar.setBounds(10, 650, 600, 100);
        panel.add(jScrollBar);

        JSlider jSlider = new JSlider();
        jSlider.setBounds(10, 800, 600, 100);
        panel.add(jSlider);
    }

三、事件监听

public class SwingControlDemo {
    
    
    private JFrame mainFrame;
    private JLabel headerLabel;
    private JLabel statusLabel;
    private JPanel controlPanel;
    public SwingControlDemo(){
    
    
        prepareGUI();
    }
    public static void main(String[] args){
    
    
        SwingControlDemo swingControlDemo = new SwingControlDemo(); 
        swingControlDemo.showEventDemo();
    }
    private void prepareGUI(){
    
    
        JFrame.setDefaultLookAndFeelDecorated(true);

        mainFrame = new JFrame("登录");
        mainFrame.setSize(400,400);
        mainFrame.setLayout(new GridLayout(3, 1)); //布局 几行几列
        headerLabel = new JLabel("",JLabel.CENTER );
        statusLabel = new JLabel("",JLabel.CENTER);
        statusLabel.setSize(350,100);
        mainFrame.addWindowListener(new WindowAdapter() {
    
      //监听
            public void windowClosing(WindowEvent windowEvent){
    
    
                System.exit(0);
            }
        });
        controlPanel = new JPanel();
        controlPanel.setLayout(new FlowLayout());
        mainFrame.add(headerLabel);
        mainFrame.add(controlPanel);
        mainFrame.add(statusLabel);
        mainFrame.setVisible(true);
    }
    private void showEventDemo(){
    
    
        headerLabel.setText("Control in action: Button");
        JButton okButton = new JButton("确定");
        JButton submitButton = new JButton("提交");
        JButton cancelButton = new JButton("取消");
        okButton.setActionCommand("OK");
        submitButton.setActionCommand("Submit");
        cancelButton.setActionCommand("Cancel");
        okButton.addActionListener(new ButtonClickListener());
        submitButton.addActionListener(new ButtonClickListener());
        cancelButton.addActionListener(new ButtonClickListener());
        controlPanel.add(okButton);
        controlPanel.add(submitButton);
        controlPanel.add(cancelButton);
        mainFrame.setVisible(true);
    }

    class ButtonClickListener implements ActionListener {
    
    
        public void actionPerformed(ActionEvent e) {
    
    
            String command = e.getActionCommand();
            if( command.equals( "OK" ))  {
    
    
                statusLabel.setText("确定按钮.");
            }
            else if( command.equals( "Submit" ) )  {
    
    
                statusLabel.setText("提交按钮.");
            }
            else  {
    
    
                statusLabel.setText("取消按钮.");
            }
        }
    }
}

学习地址： https://www.w3cschool.cn/swing/7cxu1imh.html