Java之JScrollPane:打造一个QQ好友聊天窗口

程序代码: package com.os.frame; import java.awt.BorderLayout; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swi