actiondemo.java

简单聊天程序

/*
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 * and open the template in the editor.
 */

/**
 *
 * @author Administrator
 */
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ActionDemo extends JFrame{
    JTextField jtfName;
    JTextArea jtaChat;
    JTextArea jtaInput;
    JButton jbSend;
    JButton jbClear;
    public ActionDemo(){
        super("控件的相互控制");
                Container container=this.getContentPane();
        JPanel p=new JPanel();
        jtfName=new JTextField(10);
        p.add(new JLabel("主题：Write Once,Run Anywhere. "));
        p.add(new JLabel("昵称"));
        p.add(jtfName);
        container.add(p,BorderLayout.NORTH );
        jtaChat=new JTextArea();
        container.add(new JScrollPane(jtaChat),BorderLayout.CENTER );
        Box box=new Box(BoxLayout.X_AXIS);
        jtaInput=new JTextArea(3,20);
        jbSend=new JButton();
        jbClear=new JButton();
        jbClear.setText("清除");
        box.add(new JScrollPane(jtaInput));
        box.add(jbClear);
        box.add(jbSend);
        container.add(box,BorderLayout.SOUTH );
        jbClear.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent e){
        jtaInput.setText("");
        }
        });
        Action sendMessage=new AbstractAction(){
        public void actionPerformed(ActionEvent e){
            replaceMessage();
        }
        };
        jtaInput.getInputMap().put(KeyStroke.getKeyStroke("ENTER"),"send");
        jtaInput.getActionMap().put("send",sendMessage);
        jbSend.setAction (sendMessage);
        jbSend.setText("发送");
        setSize(400,200);
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    private void replaceMessage(){
    String message=jtfName.getText()+">"+jtaInput.getText()+"\n";
    jtaChat.insert(message,jtaChat.getDocument().getLength());
    jtaInput.setText("");

    }
public static void main(String[] args){
        new ActionDemo();
}
}