北京邮电大学信通院java作业第三次

代码：
import java.awt.*; import java.awt.event.*; public class MessageGUI implements ActionListener{ Frame frame; Label sentLabel,receivedLabel; TextArea sentMsg,receivedMsg; TextField msg; Button sent,read,clear,exit; Panel labelPanel,msgPanel,tempPanel,buttonPanel; public MessageGUI(){ frame=new Frame(); sentLabel=new Label("发送信息"); receivedLabel=new Label("接受信息"); sentMsg=new TextArea(); receivedMsg=new TextArea(); msg=new TextField(); sent=new Button("发送"); read=new Button("读取"); clear=new Button("清除"); exit=new Button("退出"); labelPanel=new Panel(); msgPanel=new Panel(); tempPanel=new Panel(); buttonPanel=new Panel(); labelPanel.setLayout(new GridLayout(1,2)); labelPanel.add(sentLabel); labelPanel.add(receivedLabel); msgPanel.setLayout(new GridLayout(1,2)); msgPanel.add(sentMsg); msgPanel.add(receivedMsg); buttonPanel.setLayout(new FlowLayout()); buttonPanel.add(sent); buttonPanel.add(read); buttonPanel.add(clear);
buttonPanel.add(exit);
tempPanel.setLayout(new
GridLayout(2,1));
tempPanel.add(msg);
tempPanel.add(buttonPanel);
frame.setLayout(new
BorderLayout());

frame.add(labelPanel,BorderLayout
.NORTH);

frame.add(msgPanel,BorderLayout.C
ENTER);

frame.add(tempPanel,BorderLayout.
SOUTH);
sent.addActionListener(this);
read.addActionListener(this);

clear.addActionListener(this);
exit.addActionListener(this);
frame.setSize(600,400);
frame.setVisible(true);
}
public static void main(String[]
args) {
MessageGUI mgui=new
MessageGUI();
}
public void
actionPerformed(ActionEvent e){
Object o=e.getSource();
if(o==sent){
String
orig=sentMsg.getText();
String
current=msg.getText();
String
finalText=orig+"\n"+current;

sentMsg.setText(finalText);
msg.setText(""); } if(o==read){ String orig=receivedMsg.getText(); receivedMsg.setText(orig+"收到!\n"); } if(o==clear){
sentMsg.setText("");
}
if(o==exit){
System.exit(0);
}
}
}

运行结果：