如何在netbeans中打开JDialog表单？

Question

我已经构建了 Swing GUI 类 JDialog form(diglog_promotion) 和一个按钮。我希望在单击按钮时显示JDialog 表单，所以我已经编码了

dialog_promotion f = new dialog_promotion();                  
f.setVisible(true);

点击按钮后，报错：

还不支持

我尝试将它与 eclip 一起使用它可以工作
我做错了什么？

Answer 1

 Inside of your method Actionperformed for any particular case you want call JoptionPane.showMessageDialog(,); with the message you want. I have tried this in netbeans it works.
private void btnSaveActionPerformed(java.awt.event.ActionEvent evt)
{
 ...
 ...
 if(saveisclicked)
{
  System.out.println("Please Fill user name");
  JOptionPane.showMessageDialog(null, "Please Enter  User Name field");

}
...
...