java - jdialog 对话框打开但显示为空白

Question

我编写了以下代码来生成决策树，请稍候JDialog，但它打开并显示为空白

public JDialog pleasewait()
{
    JDialog dialog = new JDialog();
    JLabel label = new JLabel("Please wait...");
    label.setIcon(new javax.swing.ImageIcon(getClass().getResource("/decision_tree_runner/load.gif"))); // NOI18N
    dialog.setBackground(Color.BLACK);
    dialog.setLocationRelativeTo(null);
    dialog.setTitle("Please Wait...");
    dialog.add(label);
    dialog.pack();

    return dialog;

}

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
    JDialog dialog = pleasewait();
    dialog.repaint();
    dialog.setVisible(true);
    FypProject fyp_project = new FypProject();
    try {fyp_project.main_fypproject();} catch (SQLException ex) {}
    dialog.setVisible(false);

}                             

Answer 1

fyp_project.main_fypproject() 可能是一个长时间运行/阻塞的调用，当从事件调度线程的上下文中调用它时，将阻止它处理新事件，包括重绘请求。

考虑使用诸如 SwingWorker 之类的东西，首先打开对话框，执行工作线程，当调用 done 方法时，关闭对话框

看看Concurrency in Swing和 Worker Threads and SwingWorker了解更多详情