如何设置JTextArea的最大大小，如果等于或大于该大小，则可以添加滑块

Posted 2021-04-12

我目前正在使用JTextArea。我的问题是我应该如何处理JTextArea所以我可以设置一个特定的大小，如果文本太多不适合，那么在JTextArea上添加一个滑块？

这是创建我的JTextArea的方法：

public JPanel create_Output_Panel(){

    //Setup Main Panel of the Chat Application
    JPanel panel = new JPanel();
    title = BorderFactory.createTitledBorder("Server Screen");
    title.setTitleJustification(TitledBorder.CENTER);
    title.setTitleColor(Color.BLACK);
    panel.setBorder(title); //Set title to the Panel

    panel.setLayout(new BorderLayout());

    //Store IP Address in a String variable
    String ip_Address = new ChatServerViewer().getServer_IP_Addres();

    JLabel label = new JLabel("You are connected to Server : " + ip_Address, SwingConstants.CENTER);
    label.setFont(new Font("Serif", Font.PLAIN, 17));
    panel.add(label,BorderLayout.NORTH);

    JLabel label2 = new JLabel("Use .bye to log-out ", SwingConstants.CENTER);
    label2.setFont(new Font("Serif", Font.BOLD, 20));
    panel.add(label2);

    //CREATE TEXT AREA FOR THE USER MESSAGES
    textArea = new JTextArea(12,1);
    textArea.setFont(new Font("Serif", Font.PLAIN, 25));
    textArea.setEditable(false); //Block User from Editing the Text Area

    textArea.setText("

     Server:");
    textArea.append("
          Hello User !");

    panel.add(textArea, BorderLayout.SOUTH);

    return panel;
}

答案

我使用以下方法来解决问题!!

/**
 * Reference : https://stackoverflow.com/questions/10177183/java-add-scroll-into-text-area
 * Reference : https://docs.oracle.com/javase/tutorial/uiswing/components/scrollpane.html#sizing
 * @return a panel of a JTextArea inside an ScrollPane
 */
public JPanel create_Output_Panel(){

    //Setup Main Panel of the Chat Application
    JPanel panel = new JPanel();
    title = BorderFactory.createTitledBorder("Server Screen");
    title.setTitleJustification(TitledBorder.CENTER);
    title.setTitleColor(Color.BLACK);
    panel.setBorder(title); //Set title to the Panel

    panel.setLayout(new BorderLayout());

    //Store IP Address in a String variable
    String ip_Address = new ChatServerViewer().getServer_IP_Addres();

    JLabel label = new JLabel("You are connected to Server : " + ip_Address, SwingConstants.CENTER);
    label.setFont(new Font("Serif", Font.PLAIN, 17));
    panel.add(label,BorderLayout.NORTH);

    JLabel label2 = new JLabel("Use .bye to log-out ", SwingConstants.CENTER);
    label2.setFont(new Font("Serif", Font.BOLD, 20));
    panel.add(label2);

    //CREATE TEXT AREA FOR THE USER MESSAGES
    textArea = new JTextArea(15,0);
    textArea.setFont(new Font("Serif", Font.BOLD, 20));
    textArea.setEditable(false); //Block User from Editing the Text Area

    textArea.setLineWrap(true);

    JScrollPane areaScrollPane = new JScrollPane(textArea);
    areaScrollPane.setVerticalScrollBarPolicy(
            JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

    System.out.println("textArea height = " + textArea.getSize().width);
    textArea.setText("    Server>>>   ");
    textArea.append("Connection Succesful !");

    panel.add(areaScrollPane, BorderLayout.SOUTH);

    return panel;
}