各位大虾,请帮助看一个关于键盘事件的错误? 用class TextfieldListener extends KeyAdapter如果实现接口必须实现接口中的所有方法接口一般都有相应的Adapter,里面的方法都是空实现的,所以只需重载需要的方法就可以了 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 你TextfieldListener继承的是KeyListener接口,你还有两个方法没有重写!public void keyTyped(KeyEvent e){}public void keyReleased(KeyEvent e){}加上去就可以了! import java.awt.*;import java.awt.event.*;public class KeyEventDemo2 extends Frame{ private TextField tf=new TextField(10); public KeyEventDemo2() { tf.addKeyListener(new java.awt.event.KeyAdapter() { public void keyPressed(KeyEvent e) { this_keyPressed(e); } }); add(tf); pack(); setVisible(true); } void this_keyPressed(KeyEvent e) { int nKeycode=e.getKeyCode(); if(nKeycode==10) System.out.println("Key_Pressed:"+e.getKeyText(nKeycode)); } public static void main(String[] args) { KeyEventDemo2 frame=new KeyEventDemo2(); } } 同意fpwang(胖子)说的,用class TextfieldListener extends KeyAdapter,用Adapter类可以允许你只重载你所要用的方法,其它的可以不理 tf.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) {do something.} }); 我也来要点分~~import java.awt.*;import java.awt.event.*;public class KeyEventDemo extends Frame{ private TextField tf=new TextField(10); public KeyEventDemo() { tf.addKeyListener(new TextfieldListener()); add(tf); pack(); setVisible(true); } class TextfieldListener implements KeyListener { int nKeycode; public void keyPressed(KeyEvent e) { nKeycode=e.getKeyCode(); System.out.println("Key_Pressed:"+e.getKeyText(nKeycode)); } public void keyTyped(KeyEvent e){} public void keyReleased(KeyEvent e){} } public static void main(String[] args) { KeyEventDemo frame=new KeyEventDemo(); }} NetBeans中无法导入java.lang.Math java接收手机短信 问几个h i b e r n a t e的问题!不知道有没有人愿意回答! JAVA基础代码报错,求教 一面试题,如下: 为什么这个抽象类有实例! 关于类继承的问题。 高手开过来 关于java编译不通过的简单问题!烦死了! 立刻就给100分关于select数据后在jtable上显示 extends JPanel无法设布局?? 什么是脚本语言,还有什么其他类型的语言?
public void keyTyped(KeyEvent e){}
public void keyReleased(KeyEvent e){}
加上去就可以了!
import java.awt.event.*;
public class KeyEventDemo2 extends Frame
{
private TextField tf=new TextField(10);
public KeyEventDemo2()
{
tf.addKeyListener(new java.awt.event.KeyAdapter()
{
public void keyPressed(KeyEvent e)
{
this_keyPressed(e);
}
});
add(tf);
pack();
setVisible(true);
}
void this_keyPressed(KeyEvent e)
{
int nKeycode=e.getKeyCode();
if(nKeycode==10)
System.out.println("Key_Pressed:"+e.getKeyText(nKeycode));
} public static void main(String[] args)
{
KeyEventDemo2 frame=new KeyEventDemo2();
}
}
{
public void keyPressed(KeyEvent e) {do something.}
});
import java.awt.event.*;
public class KeyEventDemo extends Frame
{
private TextField tf=new TextField(10);
public KeyEventDemo()
{
tf.addKeyListener(new TextfieldListener());
add(tf);
pack();
setVisible(true);
}
class TextfieldListener implements KeyListener
{
int nKeycode;
public void keyPressed(KeyEvent e)
{
nKeycode=e.getKeyCode();
System.out.println("Key_Pressed:"+e.getKeyText(nKeycode));
}
public void keyTyped(KeyEvent e){}
public void keyReleased(KeyEvent e){} } public static void main(String[] args)
{
KeyEventDemo frame=new KeyEventDemo(); }}