我有一个相当简单的视图类，我正在构建。我一边试一试，因此代码远未完成。但是，当我测试时，一切看起来都很好，直到我滚动。如果我通过单击滚动条上的空白区域一次滚动页面，一切都很好。如果我使用滚动箭头，拖动滚动条，或使用鼠标滚轮，新显示的内容将完全损坏。这种情况同时发生在1.6.35和1.7.09。当我点击并拖动“日志行”（这是一个JTextField）时，我也注意到了错误。请告诉我，我在这里做错了。代码应该按原样运行。
package com.mycompany.utility.logs;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTextField;
import javax.swing.JTextPane;
import javax.swing.ScrollPaneConstants;
import javax.swing.border.EmptyBorder;
/**
* This class implements the log viewer view.
*/
public class LogViewer extends JFrame
{
private static final long serialVersionUID = 1L;
private static final Color TRANSPARENT = new Color(255, 255, 255, 0);
private JPanel contentPane;
/**
* Launch the application.
*/
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable() {
@Override
public void run()
{
try
{
LogViewer frame = new LogViewer();
frame.setVisible(true);
}
catch (Exception e)
{
e.printStackTrace();
}
}
});
}
/**
* Create the view.
*/
public LogViewer()
{
GridBagConstraints gridBagConstraints = null;
int row = 0;
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 713, 684);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
JPanel topPanel = new JPanel();
contentPane.add(topPanel, BorderLayout.NORTH);
GridBagLayout gbl_topPanel = new GridBagLayout();
gbl_topPanel.columnWidths = new int[] { 0 };
gbl_topPanel.rowHeights = new int[] { 0 };
gbl_topPanel.columnWeights = new double[] { Double.MIN_VALUE };
gbl_topPanel.rowWeights = new double[] { Double.MIN_VALUE };
topPanel.setLayout(gbl_topPanel);
JLabel titleLabel = new JLabel("Tattle Tail Log Viewer");
titleLabel.setFont(new Font("Lucida Sans", Font.BOLD, 12));
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridy = 0;
gridBagConstraints.gridx = 0;
topPanel.add(titleLabel, gridBagConstraints);
JPanel bottomPanel = new JPanel();
contentPane.add(bottomPanel, BorderLayout.SOUTH);
JSplitPane splitPane = new JSplitPane();
splitPane.setResizeWeight(0.75);
splitPane.setOneTouchExpandable(true);
splitPane.setOrientation(JSplitPane.VERTICAL_SPLIT);
contentPane.add(splitPane, BorderLayout.CENTER);
JPanel scrollPanel = new JPanel();
scrollPanel.setBackground(Color.WHITE);
scrollPanel.setLayout(new GridBagLayout());
JScrollPane scrollPane = new JScrollPane();
scrollPane.setViewportView(scrollPanel);
scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
splitPane.setLeftComponent(scrollPane);
final JTextPane textPane = new JTextPane();
splitPane.setRightComponent(textPane);
textPane.setFont(new Font("Courier New", Font.PLAIN, 11));
for (int i = 0; i < 25; i++)
{
addLogEntry(scrollPanel, textPane, row,
"2013-03-11 15:40:19,123 INFO com.mycompany.business.logic.ImportantProcess",
"Something of which you need to be aware happened " + i + ".");
row++;
}
JPanel fillPanel = new JPanel();
fillPanel.setBackground(Color.LIGHT_GRAY);
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = row;
gridBagConstraints.gridwidth = 2;
gridBagConstraints.weighty = 1D;
gridBagConstraints.fill = GridBagConstraints.BOTH;
scrollPanel.add(fillPanel, gridBagConstraints);
}
private void addLogEntry(final JPanel scrollPanel, final JTextPane textPane, final int row, final String logText,
final String messageText)
{
GridBagConstraints gridBagConstraints = null;
JPanel entryPanel = new JPanel();
entryPanel.setBackground(TRANSPARENT);
entryPanel.setLayout(new GridBagLayout());
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = row;
gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
gridBagConstraints.weightx = 1D;
gridBagConstraints.weighty = 0D;
gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
scrollPanel.add(entryPanel, gridBagConstraints);
JPanel logLinePanel = new JPanel();
logLinePanel.setBackground(TRANSPARENT);
logLinePanel.setFocusable(true);
logLinePanel.setLayout(new GridBagLayout());
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.weightx = 1D;
gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
entryPanel.add(logLinePanel, gridBagConstraints);
JLabel logLineLevelLabel = new JLabel(" ");
logLineLevelLabel.setOpaque(true);
logLineLevelLabel.setBackground(new Color(0, 128, 0));
logLineLevelLabel.setFont(new Font("Courier New", Font.BOLD, 11));
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
logLinePanel.add(logLineLevelLabel, gridBagConstraints);
JTextField logLineText = new JTextField(logText);
logLineText.setEditable(false);
logLineText.setBackground(TRANSPARENT);
logLineText.setBorder(null);
logLineText.setFont(new Font("Courier New", Font.PLAIN, 11));
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridx = 1;
gridBagConstraints.gridy = 0;
gridBagConstraints.weightx = 1D;
gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
logLinePanel.add(logLineText, gridBagConstraints);
JPanel messageLinePanel = new JPanel();
messageLinePanel.setBackground(TRANSPARENT);
messageLinePanel.setLayout(new GridBagLayout());
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 1;
gridBagConstraints.weightx = 1D;
gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
entryPanel.add(messageLinePanel, gridBagConstraints);
JLabel hasMoreMessageLineLabel = new JLabel("+ ");
hasMoreMessageLineLabel.setFont(new Font("Courier New", Font.BOLD, 11));
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
messageLinePanel.add(hasMoreMessageLineLabel, gridBagConstraints);
JLabel messageLineLabel = new JLabel(messageText);
messageLineLabel.setBackground(TRANSPARENT);
messageLineLabel.setFocusable(true);
messageLineLabel.setFont(new Font("Courier New", Font.PLAIN, 11));
gridBagConstraints = new GridBagConstraints();
gridBagConstraints.gridx = 1;
gridBagConstraints.gridy = 0;
gridBagConstraints.weightx = 1D;
gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
messageLinePanel.add(messageLineLabel, gridBagConstraints);
entryPanel.addMouseListener(new MouseAdapter() {
@Override
public void mouseEntered(MouseEvent e)
{
final JPanel containerPanel = (JPanel) e.getComponent();
final JPanel messagePanel = (JPanel) containerPanel.getComponent(1);
final JLabel messageLabel = (JLabel) messagePanel.getComponent(1);
String text = messageLabel.getText();
textPane.setText(text);
}
@Override
public void mouseExited(MouseEvent e)
{
textPane.setText("");
}
});
}
}
答案 0 :(得分：3)
private static final Color TRANSPARENT = new Color(255, 255, 255, 0);
我猜这是你的问题。设置透明色背景时要小心。请参阅Backgrounds With Transparency以了解这是一个问题的原因。
在您的情况下（因为您使用完全透明），您可以使用：
setOpaque( false );
答案 1 :(得分：0)
伙计，这看起来很奇怪。
对于寻找更多信息的人：滚动文本面板时，滚动面板内面板的内容不能保持其完整性;当它们的原件向下滚动时，部分字母线留在后面，使它看起来有点“融化”。换句话说，'mangling'并不意味着破坏文本，而是构成图像的像素被破坏。
我会尝试在没有GridBag的情况下在滚动面板中制作面板。我对GridBag并不熟悉，我觉得它很不愉快，并且到目前为止管理的主要是没有它。但是你的内部面板的结构看起来很简单，你也不需要它：它看起来你有一个图像左上角，然后是文本行，然后可能是另一个图像，然后是另一行文本。制作两个JPanel，每行一个，你可以使用flowlayout和水平方向，只需将图像和文本粘贴在那里，然后水平布局并将两个JPanels粘贴到面板中，现在你有一个面板，你可以添加到滚动面板。
我不知道这是否能解决问题，但是GridBag是你的代码中唯一看起来与我之前没有做过的事情不同的东西。而且我对GridBag不够轻易，很快就能弄清楚它可能出现的问题。