【发布时间】：2015-04-17 14:22:24
【问题描述】：
嗨，我在下面的代码中遇到了问题（主要是在方法“append(String str)”中）。我想以 HTML 格式显示收到的消息（所以我需要使用 JLabel）。 没有设置 tac.preferredSize 这里是我得到的：
但它不能使用没有空格的长字符串： 比如“啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊”
如果我设置 tac.preferredSize 气泡的高度不会增加：
我该如何克服这些问题？ （处理布局/大小而不修改输入字符串）
代码如下：
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ClientGUI extends JFrame implements ActionListener {
private static final long serialVersionUID = 1L;
private JLabel label;
private JTextField tf;
private JPanel chatPanel;
private JScrollPane scroll;
ClientGUI() {
super("Chat Client");
label = new JLabel("You can write messages below:", SwingConstants.CENTER);
chatPanel = new JPanel();
tf = new JTextField("");
tf.setBackground(Color.WHITE);
tf.requestFocus();
tf.setVisible(true);
tf.addActionListener(this);
chatPanel.setLayout(new BoxLayout(chatPanel, BoxLayout.PAGE_AXIS));
chatPanel.add(Box.createVerticalGlue());
JPanel centerPanel = new JPanel(new GridLayout(1,1));
scroll = new JScrollPane();
scroll.setViewportView(chatPanel);
scroll.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
scroll.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
centerPanel.add(scroll);
add(centerPanel, BorderLayout.CENTER);
JPanel southPanel = new JPanel(new BorderLayout());
JPanel writeChatPanel = new JPanel(new GridLayout(2,1));
writeChatPanel.add(label);
writeChatPanel.add(tf);
southPanel.add(writeChatPanel, BorderLayout.NORTH);
add(southPanel, BorderLayout.SOUTH);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(600, 600);
setVisible(true);
chatPanel.scrollRectToVisible(new Rectangle(chatPanel.getSize()));
}
void append(String str) {
LeftArrowBubble leftArrowBubble = new LeftArrowBubble();
leftArrowBubble.setMaximumSize(new Dimension(400,350));
JLabel tac = new JLabel();
tac.setMaximumSize(new Dimension(350,400));
//tac.setPreferredSize(new Dimension(350,50)); //<----------
System.out.println(str);
tac.setText("<html><body style='width: 350px; padding:15px;display:block;'>"+str+"</body></html>");
tac.setOpaque(false);
leftArrowBubble.add(tac, BorderLayout.NORTH);
chatPanel.add(leftArrowBubble);
chatPanel.add(Box.createRigidArea(new Dimension(0,5)));
Rectangle rect = chatPanel.getBounds();
Rectangle r2 = scroll.getViewport().getVisibleRect();
chatPanel.scrollRectToVisible(new Rectangle((int) rect.getWidth(),
(int) rect.getHeight(), (int) r2.getWidth(), (int) r2.getHeight()));
revalidate();
repaint();
}
public void actionPerformed(ActionEvent e) {
// just have to send the message
append(tf.getText());
tf.setText("");
return;
}
public static void main(String[] args) {
new ClientGUI();
}
}
还有泡泡课：
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.GeneralPath;
import javax.swing.BoxLayout;
import javax.swing.JPanel;
public class LeftArrowBubble extends JPanel {
private static final long serialVersionUID = -5389178141802153305L;
public LeftArrowBubble() {
this.setLayout(new BoxLayout(this,BoxLayout.PAGE_AXIS));
}
@Override
protected void paintComponent(final Graphics g) {
final Graphics2D graphics2D = (Graphics2D) g;
RenderingHints qualityHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
qualityHints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
graphics2D.setRenderingHints(qualityHints);
graphics2D.setPaint(new Color(80, 150, 180));
int width = getWidth();
int height = getHeight();
GeneralPath path = new GeneralPath();
path.moveTo(5, 10);
path.curveTo(5, 10, 7, 5, 0, 0);
path.curveTo(0, 0, 12, 0, 12, 5);
path.curveTo(12, 5, 12, 0, 20, 0);
path.lineTo(width - 10, 0);
path.curveTo(width - 10, 0, width, 0, width, 10);
path.lineTo(width, height - 10);
path.curveTo(width, height - 10, width, height, width - 10, height);
path.lineTo(15, height);
path.curveTo(15, height, 5, height, 5, height - 10);
path.lineTo(5, 15);
path.closePath();
graphics2D.fill(path);
}
}
【问题讨论】：
标签： java swing jlabel boxlayout