keyeventdemo.java

来自「java2应用开发指南第一版」· Java 代码 · 共 49 行

//KeyEventDemo.java
import java.awt.*;
import java.awt.event.*;

public class KeyEventDemo extends Frame 
{
	private TextField tf = new TextField(10);

	public KeyEventDemo()
	{
		tf.addKeyListener(new TextfieldListener());
		//把文本域组件加入到框架窗口中
		add(tf);
		//显示框架窗口
		pack();
		setVisible(true);
	}
	//程序的入口方法
	public static void main( String[] args ) 
	{
		KeyEventDemo frame=new KeyEventDemo();
		//设置框架窗体的事件适配器监听(关闭窗体事件)
		frame.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e)
			{
				System.exit(0);
			}
		});		
	}
	//实现了键盘事件监听器接口的类
	class TextfieldListener implements KeyListener {
		int nKeycode;
		//键盘按下事件
		public void keyPressed(KeyEvent e) {
			nKeycode=e.getKeyCode();
			System.out.println("KEY_PRESSED:  "+e.getKeyText(nKeycode));
		}
		//键盘释放事件
		public void keyReleased(KeyEvent e) {
			nKeycode=e.getKeyCode();
			System.out.println("KEY_RELEASED:  "+e.getKeyText(nKeycode));
		}
		//键盘中的非系统键
		public void keyTyped(KeyEvent e) {
			nKeycode=e.getKeyCode();
			System.out.println("KEY_TYPED:  "+e.getKeyText(nKeycode)); 
		}
	}
}