我是一个学习Java编程,并试图从书中编译下面的代码。当我尝试编译代码我得到这个错误如何解决“击键不抽象,不覆盖ab。方法”
Keystrokes is not abstract and does not override abstract method
keyTyped (java.awt.event.KeyEvent) in java.awt.event.KeyListener.
而且,我相信这是不相关的,但书中还告诉我,这部分代码添加到源代码(的地方):
pnl.add (field) ;
pnl.add (txtArea);
当我这样做,我得到一个标识符“预期的错误”。
程序代码:
import javax.swing.*;
import java.awt.event.*;
class Keystrokes extends JFrame implements KeyListener
{
JPanel pnl = new JPanel();
public static void main (String[ ] args){
Keystrokes gui = new Keystrokes();
}
JTextField field = new JTextField (38);
JTextArea txtArea = new JTextArea (5, 38);
public Keystrokes()
{
super("Swing window");
setSize(500,200);
setDefaultCloseOperation(EXIT_ON_CLOSE);
add(pnl);
field.addKeyListener (this);
setVisible(true);
}
public void keyPressed(KeyEvent event)
{
txtArea.setText("Key Pressed");
throw new UnsupportedOperationException("Not supported yet.");
}
public void KeyTyped (KeyEvent event) {
throw new UnsupportedOperationException("Not supported yet.");
txtArea.append("\nCharacter : " + event.getKeyChar());
}
public void keyReleased (KeyEvent event)
{
int keyCode = event.getKeyCode();
txtArea.append("\nKey Code : " + event.getKeyCode());
textArea.append("\nKey Text : " + event.getKeyText(keyCode));
}
}
请不要在同一时间包含多个空行的空白行。为了人们阅读和调试,对代码块使用一致的逻辑缩进。 –