Question

我的swing应用程序中遇到JTextArea的问题。 JTextArea放置在面板的顶部，其宽度应相对于下面的组件。我使用setLineWrap和setWrapStyleWord来实现这一目标。

然而，当我打包框架时，下面面板中的组件不会完全可见。我尝试过使用三种不同的布局管理器：BorderLayout，GridBagLayout和BoxLayout。

奇怪的是，使用BorderLayout和GridBagLayout，我可以通过pack ()两次调用JFrame方法来解决问题。

这里有一个当前情况的截图，在＆＃34;第二行框架＆＃34;我两次调用pack方法，除了使用BoxLayout：

的GUI之外，它似乎有效

示例代码：

import java.awt.*;
import javax.swing.*;
public class TextAreaWrappingTest
{
    public static void main (String [] a) {
        SwingUtilities.invokeLater (new Runnable () {
            @Override public void run () {
                try {
                    UIManager.setLookAndFeel (UIManager.getSystemLookAndFeelClassName ());
                    createAndShowGUI ();
                }
                catch (Exception e) {
                    e.printStackTrace ();
                }
            }
        });
    }
    private static void createAndShowGUI () {
        int locX = 0, locY = 0, maxHeight = 0;
        for (int i = 0; i < 2; i ++) {
            locX = 0;
            locY = maxHeight;
            for (String layoutType : new String [] {"BorderLayout", "BoxLayout", "GridBagLayout"}) {
                JFrame frame = new JFrame ("Test");
                frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
                frame.setContentPane (new MainPanel (layoutType));
                frame.pack ();
                if (i == 1) frame.pack ();
                frame.setLocation (locX, locY);
                locX += frame.getWidth () + 10;
                maxHeight = Math.max (locY, frame.getHeight () + 10);
                frame.setResizable (false);
                frame.setVisible (true);
            }
        }
    }
}
class MainPanel extends JPanel
{
    public MainPanel (String layoutType) {
        // Creating components
        JTextArea textArea = new JTextArea ("This text area shows a useful message for the user. The lines should wrap relative to the center panel preferred width.");
        textArea.setEditable (false);
        textArea.setFont (getFont ());
        textArea.setLineWrap (true);
        textArea.setWrapStyleWord (true);
        JPanel centerPanel = new JPanel (new FlowLayout (FlowLayout.LEFT, 10, 0));
        centerPanel.add (new JLabel ("Label :"));
        centerPanel.add (new JTextField (20));
        // Adding components
        if (layoutType.equals ("BorderLayout")) {
            setLayout (new BorderLayout (0, 20));
            add (textArea, BorderLayout.NORTH);
            add (centerPanel, BorderLayout.CENTER);
        }
        else if (layoutType.equals ("GridBagLayout")) {
            setLayout (new GridBagLayout ());
            GridBagConstraints c = new GridBagConstraints ();
            c.fill = GridBagConstraints.BOTH;
            c.weightx = 1.0;
            add (textArea, c);
            c = new GridBagConstraints ();
            c.gridy = 1;
            c.insets = new Insets (20, 0, 0, 0);
            add (centerPanel, c);
        }
        else if (layoutType.equals ("BoxLayout")) {
            setLayout (new BoxLayout (this, BoxLayout.Y_AXIS));
            add (textArea);
            add (centerPanel);
        }
        else throw new IllegalArgumentException ("Invalid layoutName argument");
    }
}

我试图在这里找到类似的答案，但我没有设法解决这个问题。我该怎么做才能避免那个双包（）？

带换行的JTextArea是隐藏组件

0 个答案: