我有一个进度对话框窗口，其中包含 3 个 JComponents:JLabel、JProgressBar、JButton，它们在不同线程的应用程序的不同部分用作默认对话框窗口。因此，当我尝试更改标签的值时，它不会清除其下方的背景，它只是在旧文本上绘制新文本。包装类不会覆盖任何方法，它只是将方法调用委托(delegate)给它包含的组件。

代码如下:

  public void setNote(String note) {
        this.note = note;
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
               label.setText(ProgressDialog.this.note);
            }
         });
    }

实际结果类似http://www.daniweb.com/forums/post1073367.html#post1073367 但该解决方案不适合我。

有人遇到过这样的问题吗？

谢谢。

这是该类(class)的剪辑版。但正如我所说，我无法使其正常工作。希望这会有所帮助。

    public class Tesssst {

    public static void main(String [] args) {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


        ProgressDialog dialog = new ProgressDialog(frame, "Title", "Message");
        dialog.showDialog(true);

    }
}

class ProgressDialog extends JComponent {
    /**
     *
     */
    private JProgressBar progressBar;
    private JLabel label;
    private JFrame parentComponent;
    private String title;
    private String note;
    private boolean canceled;
    private boolean cancelEnabled;
    private JButton btnCancel;
    private JPanel contentPanel;

    public ProgressDialog(JFrame parentComponent, String title, String message) {
        this.parentComponent = parentComponent;
        this.title = title;
        progressBar = new JProgressBar();
        label = new JLabel();
        contentPanel =new JPanel();
        canceled = false;
        cancelEnabled = true;
        setNote(message);
        setOpaque(true);

    }
    public void setNote(String note) {
        this.note = note;
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                label.setText(ProgressDialog.this.note);
            }
         });
    }

    public String getNote() {
        return note;
    }

    protected void initDialog() {
        setBorder(new EmptyBorder(6, 6, 6, 6));
        contentPanel = new JPanel();
        contentPanel.setOpaque(true);
        setLayout(new BorderLayout());
        add(contentPanel);
        btnCancel = new JButton("Cancel");
        btnCancel.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                label.setText("ololo");
            }

        });

        contentPanel.setLayout(new GridBagLayout());
        {
        GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.fill = GridBagConstraints.NONE;
            gbc.anchor = GridBagConstraints.NORTHWEST;
            gbc.insets = new Insets(2, 0, 0, 0);
            label.setOpaque(true);
            contentPanel.add(label, gbc);
        } // label

        {
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 1;
            gbc.anchor = GridBagConstraints.NORTH;
            gbc.weightx = 1;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.insets = new Insets(4, 0, 4, 0);
            contentPanel.add(progressBar, gbc);
        } // progressBar

        {
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 2;
            gbc.anchor = GridBagConstraints.NORTH;
            gbc.fill = GridBagConstraints.NONE;
            gbc.insets = new Insets(4, 0, 4, 0);
            contentPanel.add(btnCancel, gbc);
            btnCancel.setEnabled(cancelEnabled);
        } // cancel*/
    } // funciton

    public boolean isCanceled() {
        return canceled;
    }

    public void showDialog() {
        showDialog(false);
    }

    public void showDialog(boolean modal) {
        JDialog dialog = new JDialog(parentComponent, true);
        initDialog();
        dialog.getContentPane().add(contentPanel);
        dialog.setSize(400,400);
        dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        if (modal) {
            dialog.setAlwaysOnTop(true);
        }
        dialog.setVisible(true);
        dialog.toFront();
    }

    public void cancel() {
        canceled = true;
    }

}

最佳答案

尝试 setOpaque(true)在标签上，这应该会导致它清除其背景。

关于java - 在调用设置文本后，JLabel 在旧文本上绘制新文本，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/4607511/