{相关信息}

键盘事件类(KeyEvent)是容器内的任意组件获得焦点时，组件发生键击事件，当按下释放或键入某一个键时，组件对象将产生该事件。使用键盘事件必须给组件添加一个KeyListener 接口的事件处理器，该接口包含以下 3 个方法：

void keyPressed(KeyEvent e)：按下按键时发生。

void keyReleased(KeyEvent e)：松开按键时发生。

void keyTyped(KeyEvent e)：敲击键盘，发生在按键按下后，按键放开前。

{效果图}

 

{实现代码}

package sup.orange.learn;import java.awt.*;import java.awt.event.KeyEvent;import java.awt.event.KeyListener;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;/** * Created by re-x on 10/31/14. */public class KeyEventDemo extends Frame implements KeyListener {    TextArea textarea, textarea1;    Button button;    public KeyEventDemo () {        super();        init();    }    public static void main(String[] args) {        new KeyEventDemo();    }    public void init() {        setLayout(new GridLayout(3, 1));        textarea = new TextArea();        textarea1 = new TextArea();        add(textarea);        button = new Button("click me first, then click any other key");        add(button);        button.addKeyListener(this);        add(textarea1);        addWindowListener(new WindowAdapter() {            @Override            public void windowClosing(WindowEvent e) {                super.windowClosing(e);                dispose();                System.exit(0);            }        });        setSize(200, 300);        setVisible(true);    }    public void keyPressed(KeyEvent e) {        textarea.setText("key pressed");    }    public void keyReleased(KeyEvent e) {        textarea.setText("key released");    }    public void keyTyped(KeyEvent e) {        textarea1.setText(String.valueOf(e.getKeyChar()));    }}