JavaSE 键盘事件类（KeyEvent）实现

{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()));

    }

}