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我有一个相当简单的视图类，我正在构建它。我边走边测试，所以代码远未完成。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开放区域一次滚动页面，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被破坏。1.6.35 和 1.7.09 都会出现这种情况。当我单击并拖动作为 JTextField 的“日志行”时，我还注意到了重整。请告诉我我在这里做错了什么。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("");
            }
        });
    }
}
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2 回答 2

3 
private static final Color TRANSPARENT = new Color(255, 255, 255, 0);

我猜那是你的问题。使用透明颜色设置背景时要小心。请参阅具有透明度的背景以了解为什么这是一个问题。

在您的情况下（因为您使用的是完全透明），您可以使用：

setOpaque( false );
于 2013-03-12T16:07:24.223 回答
0

人啊，长得真奇怪。

对于任何想了解更多信息的人：滚动文本面板时，滚动面板中的面板内容无法保持其完整性；部分字母行留在后面，而它们的原件向下滚动，使它看起来有点“融化”。换句话说，“修改”并不意味着修改文本，而是修改了构成图像的像素。

我会尝试在没有 GridBag 的滚动面板中制作面板。我对 GridBag 不是很熟悉，我觉得它很不愉快，而且到目前为止，我几乎不用它。但是你的内部面板的结构看起来很简单，你也不需要它：看起来你有一个左上角的图像，然后是一个文本行，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，您可以使用 flowlayout 和水平方向并将图像和文本粘贴在那里，然后水平布局并将两个 JPanel 粘贴到一个面板中，现在您有了一个面板，您可以添加到滚动面板。

我不知道这是否能解决问题，但 GridBag 是您的代码中唯一看起来与我之前所做的事情不同但没有这种行为的东西。而且我只是对 GridBag 不够灵活，无法快速找出它可能出了什么问题。

于 2013-03-12T15:58:28.670 回答