14. 74. 2. 一个简单的对话框A Simple Modal Dialog

import java.awt.BorderLayout;import java.awt.Dimension;import java.awt.Point;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JButton;import javax.swing.JDialog;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;public class AboutDialog extends JDialog implements ActionListener{public AboutDialog(JFrame parent, String title, String message){super(parent,title,true);if(parent != null){//只要窗口不为空Dimension parentSize = parent.getSize();//得到一个尺寸  窗口获得的尺寸Point p = parent.getLocation();//窗口的位置这个点给p//设置位置为setLocation(p.x + parentSize.width/4, p.y + parentSize.height/4);}JPanel messagePanel = new JPanel();messagePanel.add(new JLabel(message));getContentPane().add(messagePanel);JPanel buttonPanel = new JPanel();JButton button = new JButton("OK");buttonPanel.add(button);button.addActionListener(this);getContentPane().add(buttonPanel,BorderLayout.SOUTH);setLocationRelativeTo(parent);setDefaultCloseOperation(DISPOSE_ON_CLOSE);pack();setVisible(true);}public static void main(String[] args) {AboutDialog ad = new AboutDialog(new JFrame(),"title","message");}@Overridepublic void actionPerformed(ActionEvent e) {setVisible(false);dispose();//隐藏}}