JScrollPane 不在 JTextArea 中滚动

debugcn 发表于 Dev

阿塔西卡

有一点我不明白。我的代码JScrollBar显然不喜欢。我添加了它，但不能水平或垂直滚动。

这是它的样子：

请记住，我是新手并且我仍在努力，所以如果这是非常明显且容易避免的事情，我很抱歉。

public ChangeLog() {

    //Init.
    JFrame frame = new JFrame();
    JPanel panel = new JPanel();
    JTextArea textarea = new JTextArea();
    JScrollPane scrollpane = new JScrollPane(textarea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

    //Text Stuff
    textarea.setFont(textarea.getFont().deriveFont(16f));
    textarea.setText("Change Log: \n V1.0(A): Original encoder \n V1.0(B): Original decoder \n V1.1: Combination of both encoder and decoder \n V1.2: Added a heavier encoding & decoding system \n V1.3: Added an icon \n V1.4: Created an 'Info' page \n V1.5: Added a 'Change Log' page to the 'Info' page \n "
            + "V1.6: Removed the 'Change Log' \n V1.7: Added a 'Change Log' but was not implemented \n V1.8: Added a the 'Change Log' button \n V1.9: Added horizontal and vertical scroll bars to the 'Change Log'");
    textarea.setForeground(Color.BLACK);
    Dimension d = new Dimension(250, 275);
    textarea.setPreferredSize(d);

    //Other Stuff
    scrollpane.setViewportView(textarea);
    scrollpane.getPreferredSize();

    //Layout
    panel.setLayout(null);
    scrollpane.setBounds(new Rectangle(new Point(20, 20), scrollpane.getPreferredSize()));
    textarea.setBounds(new Rectangle(new Point(20, 23), textarea.getPreferredSize()));

    //Frame Stuff
    frame.setAlwaysOnTop(true);
    frame.setSize(300, 350);
    frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    frame.setVisible(true);
    frame.setResizable(false);

    //Panel Stuff
    frame.add(panel);
    panel.setSize(frame.getSize());
    panel.setBackground(Color.BLUE);
    panel.add(textarea);
    panel.add(scrollpane);
} }

安全的

我已经创建了一个有效的解决方案。也做了一些改动。

public TestClass() {

        //Init.
        JFrame frame = new JFrame();
        JPanel panel = new JPanel(new BorderLayout());
        JTextArea textarea = new JTextArea();
        JScrollPane scrollpane = new JScrollPane(textarea);
        panel.add(scrollpane, BorderLayout.CENTER);



        //Text Stuff
        textarea.setFont(textarea.getFont().deriveFont(16f));
        textarea.setText("Change Log: \n V1.0(A): Original encoder \n V1.0(B): Original decoder \n V1.1: Combination of both encoder and decoder \n V1.2: Added a heavier encoding & decoding system \n V1.3: Added an icon \n V1.4: Created an 'Info' page \n V1.5: Added a 'Change Log' page to the 'Info' page \n "
                + "V1.6: Removed the 'Change Log' \n V1.7: Added a 'Change Log' but was not implemented \n V1.8: Added a the 'Change Log' button \n V1.9: Added horizontal and vertical scroll bars to the 'Change Log'");
        textarea.setForeground(Color.BLACK);
        //Dimension d = new Dimension(250, 275);
        //textarea.setPreferredSize(d);


        //Other Stuff
        scrollpane.setViewportView(textarea);
        scrollpane.getPreferredSize();




        //Layout
        //scrollpane.setBounds(new Rectangle(new Point(20, 20), scrollpane.getPreferredSize()));
        //textarea.setBounds(new Rectangle(new Point(20, 23), textarea.getPreferredSize()));

        //Listeners



        //Frame Stuff
        frame.setAlwaysOnTop(true);
        frame.setSize(300, 350);
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.setVisible(true);
        frame.setResizable(false);


        //Panel Stuff
        frame.add(panel);
        panel.setSize(frame.getSize());
        panel.setBackground(Color.BLUE);
        panel.add(scrollpane);
    }

此外，当 Swing 更好地与布局管理器配合使用时，空布局将导致在不同屏幕类型上的外观不一致。

如果还需要什么，请告诉我。是的，每个人都从头开始。我仍然在学习。你也会得到很多东西。只要保持学习的渴望。:-)

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