j_keyboard.java.bak

一个十分好的java基础学习的课件

// ////////////////////////////////////////////////////////
// 
// J_Keyboard.java
// 
// Created by Jun-Hai Yong,    on XX xx, xxxx (Date)
// ////////////////////////////////////////////////////////
// Readme:
//      Keyboard event handling.
// ////////////////////////////////////////////////////////
// Using this example, please explicitly refer to the book:
//     Jun-Hai Yong. Programming in Java. 
//     Beijing: Tsinghua University Press, 2004.
// 使用本例子，请注明引用:
//     雍俊海. Java 程序设计. 北京: 清华大学出版社, 2004.
// Please note that the author and publisher make no 
// warranty of any kind on the examples provided.
// ////////////////////////////////////////////////////////

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class J_Keyboard extends JFrame
{
    String  m_string= "";

    public J_Keyboard( )
    {
        super("Example of Keyboard event handling");
        addFocusListener( new FocusListener( )
            {
                public void focusGained(FocusEvent e)
                {
                    System.out.println("Get focus!\n");
                } // End of method: focusGained
                public void focusLost(FocusEvent e)
                {
                    System.out.println("Lose focus!\n");
                } // End of method: focusLost
            } // End of the anonymous inner class, which implements FocusListener
        ); // End of invoking addFocusListener

        addKeyListener( new KeyAdapter( )
            {
                public void keyTyped(KeyEvent e)
                {
                    char [] c = {' '};
                    c[0] = e.getKeyChar( );
                    m_string= new String(c, 0, 1);
                    repaint( );
                } // End of method: keyTyped
            } // End of the anonymous inner class, which implements KeyAdapter
        ); // End of invoking addKeyListener
        
        setSize(250, 100);
        setVisible(true);
    } // End of constructor: J_Keyboard

    public void paint(Graphics g)
    {
        Dimension d=getMaximumSize( );
        g.clearRect(0, 0, d.width, d.height);
        g.drawString(m_string, 120, 55);
    } // End of method: paint

    public static void main( String args[] )
    { 
        JFrame app = new J_Keyboard( );

        Container cp = app.getContentPane( );
        app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE );
    } // End of method: main

} // End of class: J_Keyboard