Question

我正在研究一种可以告诉财富的Java GUI。代码有效，但我有一些美学问题。我已经在这里和其他网站上查看了一些内容，但我似乎无法让我的滚动窗格出现。如果有人能指出我正确的方向让这些工作，将不胜感激！

package FortuneTellerRunner;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;


/**
*
* @author a3cal_000
*/
class FortuneTellerFrame extends JFrame
{
final private JPanel mainPnl, titlePnl, displayPnl, buttonPnl, imagePnl;
final private JButton quitBtn, rndBtn;
 final private JLabel titleLbl;
final private JTextArea textArea; 
public String[] fortune = new String [12];
int newIndex, oldIndex;

private static final int HEIGHT = 250;
private static final int WIDTH = 450;

public FortuneTellerFrame()
{
  setSize(WIDTH, HEIGHT);  
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  mainPnl = new JPanel();
  mainPnl.setLayout(new BorderLayout());

  imagePnl = new JPanel();

  displayPnl = new JPanel();
  buttonPnl = new JPanel();

  titlePnl = new JPanel();

  ImageIcon icon1 = new ImageIcon("FortuneTellerIcon.JPG");
  JLabel iconLbl = new JLabel();
  iconLbl.setIcon(icon1);

  titleLbl = new JLabel("Fortune Teller!");

  textArea = new JTextArea(5, 30);  
  JScrollPane scrollPane = new JScrollPane(textArea);
  scrollPane.setPreferredSize(new Dimension(300, 250));

  // Create the layout of the title panel
  titlePnl.setLayout(new GridLayout(2,1));

  add(mainPnl);

  // Set the label to the panel.
  titlePnl.add(titleLbl);
  titlePnl.add(iconLbl);  


    // add the panel to the main panel.
    mainPnl.add(titlePnl, BorderLayout.NORTH);
    mainPnl.add(scrollPane, BorderLayout.CENTER);
    mainPnl.add(textArea, BorderLayout.CENTER);       

    // Create the "Get my fortune button.
    rndBtn = new JButton("Get My Fortune!");
    quitBtn = new JButton("Quit");



    // Add the buttons to the buttonPnl in grid layout.
    buttonPnl.add(rndBtn);
    buttonPnl.add(quitBtn);

    // Create the grid layout for the button panel.
    buttonPnl.setLayout( new GridLayout(1, 2));

    // Add the button panel to the grid layout, South.
    mainPnl.add(buttonPnl, BorderLayout.SOUTH);    


    ActionListener listener = new RndButtonListener();
    rndBtn.addActionListener(listener);
    quitBtn.addActionListener(listener);

}


class RndButtonListener implements ActionListener
{
    public void actionPerformed(ActionEvent evt)
    {
        fortune[0] = "He who throws dirt is losing ground.";
        fortune[1] = "You will find the love of your life in food.";
        fortune[2] = "Do or do not, there is no try.";
        fortune[3] = "Tomorrow is a better day to try anything of importance.";
        fortune[4] = "Life's not about how hard you can hit, but how hard you can get hit and keep moving forward.";
        fortune[5] = "You can't be late until you show up.";
        fortune[6] = "If you think things can't get worse it's probably only because you lack sufficent imagination.";
        fortune[7] = "If youre at the top it means you have further to fall.";
        fortune[8] = "Even in last place, youre still in the race.";
        fortune[9] = "The road to riches is paved on the failures of others.";
        fortune[10] = "If you feel like your going no where, get off the treadmill.";
        fortune[11] = "Thinking about going to the gym is just as good as going.";       

        Random rnd = new Random();
        do
        {
        newIndex = (int) Math.round(Math.random() * (fortune.length - 1));
        }

          while(newIndex == oldIndex);

        do
        {
            System.out.println(fortune[newIndex]);

            textArea.append(fortune[newIndex] + "\n");
            textArea.updateUI();
            mainPnl.updateUI();
            oldIndex = newIndex;

        } 
            while(newIndex != oldIndex);

        class QuitButtonListener implements ActionListener
        {
            public void actionPerformed(ActionEvent evt)
            {
                System.exit(0);
            }        

        }

     }
 }

}
再次感谢！

Answer 1

您正在将scrollPane（包含textArea）和 textArea添加到mainPn1中：

mainPnl.add(titlePnl, BorderLayout.NORTH);
mainPnl.add(scrollPane, BorderLayout.CENTER);
mainPnl.add(textArea, BorderLayout.CENTER);

您应该只添加scrollPane：

mainPnl.add(titlePnl, BorderLayout.NORTH);
mainPnl.add(scrollPane, BorderLayout.CENTER);

Answer 2

mainPnl.add(scrollPane, BorderLayout.CENTER);
mainPnl.add(textArea, BorderLayout.CENTER);

使用textarea覆盖borderlayout的中心。删除 mainPnl.add（textArea，BorderLayout.CENTER）; ，它应该可以工作。

Answer 3

这是创建文本区域的代码，使其成为滚动窗格的客户端，并将滚动窗格添加到容器中：

textArea = new JTextArea(5, 30);
JScrollPane scrollPane = new JScrollPane(textArea);
setPreferredSize(new Dimension(450, 110));
add(scrollPane, BorderLayout.CENTER);

在Java GUI中添加滚动窗格

3 个答案: