import java.awt.*;
import java.awt.event.*;public class T4 extends Frame implements KeyListener
{
Label ll;
public T4()
{
super("KeyEvent事件处理测试");
this.setBounds(300,300,500,300);
ll=new Label("显示按键");
this.addKeyListener(this);
this.add(ll);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
this.setVisible(true);
}
public static void main(String[] args) {
new T4();
} public void keyTyped(KeyEvent e) {
} public void keyPressed(KeyEvent e) {
//String s=new String();
ll.setText(String.valueOf(e.getKeyChar())); } public void keyReleased(KeyEvent e) {
}
}this.addKeyListener(this);//我想问一下为什么是窗口要注册监听器,为什么不是labal ll注册监听器
希望各位大侠能够指教一下,谢谢!!
import java.awt.event.*;public class T4 extends Frame implements KeyListener
{
Label ll;
public T4()
{
super("KeyEvent事件处理测试");
this.setBounds(300,300,500,300);
ll=new Label("显示按键");
this.addKeyListener(this);
this.add(ll);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
this.setVisible(true);
}
public static void main(String[] args) {
new T4();
} public void keyTyped(KeyEvent e) {
} public void keyPressed(KeyEvent e) {
//String s=new String();
ll.setText(String.valueOf(e.getKeyChar())); } public void keyReleased(KeyEvent e) {
}
}this.addKeyListener(this);//我想问一下为什么是窗口要注册监听器,为什么不是labal ll注册监听器
希望各位大侠能够指教一下,谢谢!!
"Frame implements KeyListener",Frame实现了KeyListener接口,而Label尚未实现这个接口。