import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JPanel;

public class ShowFrame extends JFrame implements ActionListener {
    private JButton b;
    
    private JPanel p;
    
    public ShowFrame(String title) {
        super(title);
        
        p = new JPanel();
        
        b = new JButton(\"Show\");
        b.addActionListener(this);
        
        p.add(b);
        
        getContentPane().add(p);
    }
    
    public void actionPerformed(ActionEvent e) {
        new TempFrame(this);
    }
    
    public static void main(String[] args) {
        ShowFrame f = new ShowFrame(\"ShowFrame\");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setSize(200,400);
        f.setVisible(true);
    }
}
class TempFrame extends JDialog {
    public TempFrame(ShowFrame f) {
        super(f,\"Temp\",true);
        
        setSize(100,100);
        setVisible(true);
    }
}

现在show已经过时了,不推荐 使用了
取而代之的是setVisible(true)

哦，谢谢各位了