关于弹出对话筐！！！

Question

问题解决了一半！
－－－－－－－－－－
if (dialog==null)
   dialog=new DialogPanel();
else if(!dialog.isVisible())
  {
   dialog.setVisible(true);
    }
else if (dialog.isVisible())
  {
dialog.setVisible(false);
}----------------------------------
可是还是不能定位到父面板上面，，，
调用 super()出错，why?

Answer 1

首先在Dialog的构造函数中有一个Frame参数你没有填，就选用父面板作参数。第二用setLocation]来定位就可居中了。

Answer 2

我添了但报错呀，你这样说我很模糊呀，
请帮我添一下，再setLocation()一下，谢谢!!!!

Answer 3

如果好用，最后别忘了结账。import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;class MySecondProgram extends JFrame {
    public MySecondProgram() {
        setTitle("mysecond");
        setSize(400,300);
        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        
        Container contentPane=getContentPane();
        
        JPanel northpanel=new JPanel();
        
        JButton button=new JButton("out");
        
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                Container c = dialog.getParent();
            Point p = c.getLocation();
            Dimension d = c.getSize();
            dialog.setLocation(p.x + (d.width - dialog.getWidth())/2, p.y + (d.height - dialog.getHeight())/2);
            dialog.show();
                
            }
        });
        northpanel.add(button);
        
        contentPane.add(northpanel ,BorderLayout.NORTH);
    }
    
    class DialogPanel  extends JDialog implements ActionListener {
        public DialogPanel(Frame f) {
            super(f,true);
            setSize(200,150);
            
        }
        public void actionPerformed(ActionEvent event) {
            
        }
    }
    
    public static void main(String[] args)
    {
        JFrame f = new MySecondProgram();
        f.setSize(640, 480);
        f.show();
    }
    private     JButton button;
    private     DialogPanel   dialog = new DialogPanel(this);
}