单击按钮时滚动到文本区域中的某个位置。

Question

创建像this sample 这样的HTML 链接位置很容易，但现在我要讨论的是Java swing。

假设我创建了 5 个JButtons：firstButton、secondButton、thirdButton、fourthButton 和 fifthButton。 然后我把所有的文字信息放在一个JTextArea txtInform。

当我单击firstButton 时，firstButton 的信息将显示在txtInform 的顶部。

当我单击secondButton 时，secondButton 的信息将显示在txtInform 的顶部。

等下一个按钮。所有按钮都必须像this sample 一样工作。 我该怎么做？

注意： 我知道如何在 java swing 中创建组件（如 JButton、JTextArea 等）。请不要告诉我只看Swing Class API 或其他java docs 的教程。我已经阅读了 Swing Class API 教程和java docs，但我还没有找到任何针对这个问题的具体教程。如果您曾经阅读过像我在这里问的那样的特定教程，请告诉我。

编辑：

更新：我真正需要的是在单击按钮时滚动到文本区域中的某个位置。

以下是我目前的代码，我是在 netbeans 中创建的。我使用来自here 的高光。

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

package gui_001;

import java.awt.Color;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultHighlighter;
import javax.swing.text.Highlighter;

/**
 *
 * @author MyScript
 */
public class sampleFrame extends javax.swing.JFrame {

    /**
     * Creates new form sampleFrame
     */
    public sampleFrame() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        firstButton = new javax.swing.JButton();
        secondButton = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        txtInform = new javax.swing.JTextArea();
        thirdButton = new javax.swing.JButton();
        fourthButton = new javax.swing.JButton();
        fifthButton = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        firstButton.setText("First Button");
        firstButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                firstButtonActionPerformed(evt);
            }
        });

        secondButton.setText("Second Button");
        secondButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                secondButtonActionPerformed(evt);
            }
        });

        txtInform.setText("*First*");
        txtInform.append("\n");
        txtInform.append("All first information are here..");
        txtInform.append("\n\n\n\n");
        txtInform.append("**Second**");
        txtInform.append("\n");
        txtInform.append("All second information are here..");
        txtInform.append("\n\n\n\n");
        txtInform.append("***Third***");
        txtInform.append("\n");
        txtInform.append("All third information are here..");
        txtInform.append("\n\n\n\n");
        txtInform.append("****Fourth****");
        txtInform.append("\n");
        txtInform.append("All fourth information are here..");
        txtInform.append("\n\n\n\n");
        txtInform.append("*****Fifth*****");
        txtInform.append("\n");
        txtInform.append("All fifth information are here..");
        txtInform.setColumns(20);
        txtInform.setLineWrap(true);
        txtInform.setRows(5);
        txtInform.setWrapStyleWord(true);
        jScrollPane1.setViewportView(txtInform);

        thirdButton.setText("Third Button");
        thirdButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                thirdButtonActionPerformed(evt);
            }
        });

        fourthButton.setText("Fourth Button");
        fourthButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                fourthButtonActionPerformed(evt);
            }
        });

        fifthButton.setText("Fifth Button");
        fifthButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                fifthButtonActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(76, 76, 76)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(secondButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(firstButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(thirdButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(fourthButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(fifthButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addGap(64, 64, 64)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 265, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(71, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(76, 76, 76)
                .addComponent(firstButton, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(secondButton, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(thirdButton, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(fourthButton, javax.swing.GroupLayout.PREFERRED_SIZE, 32, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(fifthButton, javax.swing.GroupLayout.PREFERRED_SIZE, 32, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(44, Short.MAX_VALUE)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 305, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(90, Short.MAX_VALUE))
        );

        setSize(new java.awt.Dimension(595, 477));
        setLocationRelativeTo(null);
    }// </editor-fold>                        

    private void secondButtonActionPerformed(java.awt.event.ActionEvent evt) {                                             
        String text = txtInform.getText();
        String second = "**Second**";
        int i = text.indexOf(second);
        int pos = txtInform.getCaretPosition(); 

        Highlighter.HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter( Color.BLUE );

        int offset = text.indexOf(second);
        int length = second.length();

        while ( offset != -1)
        {
            try
            {
                txtInform.getHighlighter().addHighlight(offset, offset + length, painter);
                offset = text.indexOf(second, offset+1);
            }
            catch(BadLocationException ble) { System.out.println(ble); }
        }

    }                                            

    private void firstButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
        String text = txtInform.getText();
        String second = "*First*";
        int i = text.indexOf(second);
        int pos = txtInform.getCaretPosition(); 

        Highlighter.HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter( Color.BLUE );

        int offset = text.indexOf(second);
        int length = second.length();

        while ( offset != -1)
        {
            try
            {
                txtInform.getHighlighter().addHighlight(offset, offset + length, painter);
                offset = text.indexOf(second, offset+1);
            }
            catch(BadLocationException ble) { System.out.println(ble); }
        }
    }                                           

    private void fifthButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
        String text = txtInform.getText();
        String second = "*****Fifth*****";
        int i = text.indexOf(second);
        int pos = txtInform.getCaretPosition(); 

        Highlighter.HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter( Color.BLUE );

        int offset = text.indexOf(second);
        int length = second.length();

        while ( offset != -1)
        {
            try
            {
                txtInform.getHighlighter().addHighlight(offset, offset + length, painter);
                offset = text.indexOf(second, offset+1);
            }
            catch(BadLocationException ble) { System.out.println(ble); }
        }
    }                                           

    private void fourthButtonActionPerformed(java.awt.event.ActionEvent evt) {                                             
         String text = txtInform.getText();
        String second = "****Fourth****";
        int i = text.indexOf(second);
        int pos = txtInform.getCaretPosition(); 

        Highlighter.HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter( Color.BLUE );

        int offset = text.indexOf(second);
        int length = second.length();

        while ( offset != -1)
        {
            try
            {
                txtInform.getHighlighter().addHighlight(offset, offset + length, painter);
                offset = text.indexOf(second, offset+1);
            }
            catch(BadLocationException ble) { System.out.println(ble); }
        }
    }                                            

    private void thirdButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
         String text = txtInform.getText();
        String second = "***Third***";
        int i = text.indexOf(second);
        int pos = txtInform.getCaretPosition(); 

        Highlighter.HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter( Color.BLUE );

        int offset = text.indexOf(second);
        int length = second.length();

        while ( offset != -1)
        {
            try
            {
                txtInform.getHighlighter().addHighlight(offset, offset + length, painter);
                offset = text.indexOf(second, offset+1);
            }
            catch(BadLocationException ble) { System.out.println(ble); }
        }
    }                                           

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(sampleFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(sampleFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(sampleFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(sampleFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new sampleFrame().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton fifthButton;
    private javax.swing.JButton firstButton;
    private javax.swing.JButton fourthButton;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JButton secondButton;
    private javax.swing.JButton thirdButton;
    private javax.swing.JTextArea txtInform;
    // End of variables declaration                   
}

Answer 1

这是您的代码，其中有一些更改。按下按钮时，文本区域将滚动到文本所在的位置，只有该文本会被突出显示。

public class SampleFrame extends JFrame {

    private static JTextArea txtInform = new JTextArea();
    private static final String TEXT = "*First*\nAll first information are here..\n\n\n\n" +
            "**Second**\nAll second information are here..\n\n\n\n" +
            "***Third***\nAll third information are here..\n\n\n\n" +
            "****Fourth****\nAll fourth information are here..\n\n\n\n" +
            "*****Fifth*****\nAll fifth information are here..";

    public SampleFrame() {

        initComponents();
    }

    private void initComponents() {

        JScrollPane jScrollPane1 = new JScrollPane(txtInform);
        JButton firstButton = new JButton("First Button");
        JButton secondButton = new JButton("Second Button");
        JButton thirdButton = new JButton("Third Button");
        JButton fourthButton = new JButton("Fourth Button");
        JButton fifthButton = new JButton("Fifth Button");

        firstButton.addActionListener(new MyActionListener("*First*"));
        secondButton.addActionListener(new MyActionListener("**Second**"));
        thirdButton.addActionListener(new MyActionListener("***Third***"));
        fourthButton.addActionListener(new MyActionListener("****Fourth****"));
        fifthButton.addActionListener(new MyActionListener("*****Fifth*****"));

        txtInform.setText(TEXT);
        txtInform.setColumns(20);
        txtInform.setRows(5);
        txtInform.setLineWrap(true);
        txtInform.setWrapStyleWord(true);

        GroupLayout layout = new GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(76, 76, 76)
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING, false)
                    .addComponent(secondButton, GroupLayout.DEFAULT_SIZE,
                                GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(firstButton, GroupLayout.DEFAULT_SIZE,
                                GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(thirdButton, GroupLayout.DEFAULT_SIZE,
                                GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(fourthButton, GroupLayout.DEFAULT_SIZE,
                                GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(fifthButton, GroupLayout.DEFAULT_SIZE,
                                GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addGap(64, 64, 64)
                .addComponent(jScrollPane1, GroupLayout.PREFERRED_SIZE, 265,
                            GroupLayout.PREFERRED_SIZE).addContainerGap(71, Short.MAX_VALUE)));
        layout.setVerticalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(76, 76, 76)
                .addComponent(firstButton, GroupLayout.PREFERRED_SIZE, 30,
                            GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(secondButton, GroupLayout.PREFERRED_SIZE, 31,
                            GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(thirdButton, GroupLayout.PREFERRED_SIZE, 31,
                            GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(fourthButton, GroupLayout.PREFERRED_SIZE, 32,
                            GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(fifthButton, GroupLayout.PREFERRED_SIZE, 32,
                            GroupLayout.PREFERRED_SIZE)
                .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
            .addGroup(GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(44, Short.MAX_VALUE)
                .addComponent(jScrollPane1, GroupLayout.PREFERRED_SIZE, 305,
                            GroupLayout.PREFERRED_SIZE).addContainerGap(90, Short.MAX_VALUE)));

        setSize(new java.awt.Dimension(595, 477));
        setLocationRelativeTo(null);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }

    private class MyActionListener implements ActionListener {

        private int offset, length;
        private final Highlighter.HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter(Color.BLUE);

        private MyActionListener(String chapter) {

            offset = TEXT.indexOf(chapter);
            length = chapter.length();
        }

        public void actionPerformed(ActionEvent e) {

            txtInform.setCaretPosition(offset);
            txtInform.getHighlighter().removeAllHighlights();
            try {
                txtInform.getHighlighter().addHighlight(offset, offset + length, painter);
            } catch (BadLocationException ble) {
                ble.printStackTrace();
            }
        }
    }

    public static void main(String args[]) {

        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {

                new SampleFrame().setVisible(true);
            }
        });
    }
}

• 根据 Java 命名约定，类名以大写开头。
• 使您的代码呈现出行的逻辑顺序。一个接一个地初始化所有按钮，而不是将滚动窗格初始化推到中间，这样会更清楚。
• 当您可以创建局部变量时不要创建字段（所有按钮和滚动窗格）。
• 使用应显示的文本准备一个字符串，而不是为每一行调用 append（如果您还没有这样做的话）。
• 为所有按钮创建 1 个动作侦听器，因为它对所有按钮都有类似的功能 - 可重用代码。

如果您自己编写 GUI，而不是与构建器一起编写，您将受益匪浅。

Answer 2

简单示例

public class Main extends JPanel implements ActionListener{
    JTextField textField = null;
public static void main(final String[] args) { 
Main main =  new Main();
main.textField= new JTextField("Sample");
JButton btn1 = new JButton("Button1");
btn1.addActionListener(main);
JButton btn2 = new JButton("Button2");
btn2.addActionListener(main);

main.add(main.textField);
main.add(btn1);
main.add(btn2);
JFrame frame = new JFrame();
frame.setTitle("Simple example");
frame.setSize(300, 200);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.add(main);
frame.setVisible(true);
}

@Override
public void actionPerformed(ActionEvent e) {
    textField.setText(e.getActionCommand());
    repaint();

}

}