如何在Swing中向JTextArea添加垂直滚动条？

Question

我有这个Gui课程：

public class Gui extends JFrame implements ActionListener {

/**
 * 
 */
private static final long serialVersionUID = -384241835772507459L;
JLabel playerInfo;
JTextField textField;
private final static String newline = "\n";
JTextArea feed;
JScrollPane scrollPane;
Player player;

public Gui() {
    super("Erik's RPG");        
    setLayout(new FlowLayout());        
    textField = new JTextField(30);     
    textField.addActionListener(this);      
    feed = new JTextArea(15, 30);
    feed.setEditable(false);    
}

public void setCurrentPlayer(Player currentPlayer) {
    player = currentPlayer;
    playerInfo = new JLabel("Health = " + currentPlayer.getHealth() + " | Mana = " + player.getMana());
    playerInfo.setBorder(BorderFactory.createTitledBorder(currentPlayer.getName()));
    add(playerInfo);
    add(feed);
    add(textField);
}

当一堆文本在文本字段中时，它很烦人，因为它会使窗口变大。我需要知道如何制作滚动条，以便用户不必继续调整其JFrame的大小。另外，如何锁定JFrame的尺寸以便用户可以控制尺寸？

Answer 1

将JTextArea实例设置为JScrollPane实例的视口视图，如How to Use Scroll Panes所示。将此滚动窗格添加到框架的内容窗格中。