照抄书上代码报错： 不是抽象的，并且未覆盖 java.awt.event.KeyListener 中的抽象方法KeyReleased
下面的代码报错：
Dazi 不是抽象的，并且未覆盖 java.awt.event.KeyListener 中的抽象方法KeyReleased(java.awt.event.KeyEvent)
import java.text.DecimalFormat;
import javax.swing.border.*;
import javax.swing.border.EtchedBorder;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Dazi extends JPanel implements KeyListener{
JLabel lbl1,lbl2,lbl3,lbl4,msg;
String str="When Isaac Newton said"Every action has an equal and opposite reaction"he demonstrated he knew a lot about
physics and absolutely nothing about women.";
String substr="";
JTextArea txt;
int index=0;
double count=0;
DecimalFormat form1=new DecimalFormat("0.000"); //指定数字输出格式保留3位小数
public static void main(String args[]){
JFrame f=new JFrame("练习英文打字");
Dazi da=new Dazi();
JPanel pane=da.init();
JPanel p=new JPanel();
f.getContentPane().add(pane);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(300,250);
f.setVisible(true);
}
public JPanel init(){
JPanel p=new JPanel(new FlowLayout(FlowLayout.LEADING));
lbl1=new JLabel("When Isaac Newton said"Every action");
lbl2=new JLabel("has an equal and opposite reaction"");
lbl3=new JLabel("he demonstrated he knew a lot about physics");
lbl4=new JLabel("and absolutely nothing about women.");
msg=new JLabel("请输入上面的文字");
txt=new JTextArea(5,25);
txt.setEditable(false);
txt.setLineWrap(true); //设置自动换行
/* txt.setBorder(BorderFactory.cteateEtchedBorder(EtchedBorder.RAISED));*/
p.add(lbl1); p.add(lbl2); p.add(lbl3); p.add(lbl4);
p.add(msg); p.add(txt);
txt.addKeyListener(this);
return p;
}
public void KeyTyped(KeyEvent e){
count++;
if(index!=str.length()){
if(String.valueOf(e.getKeyChar()).equals(str.substring(index,index+1))){
substr=str.substring(0,index+1);
txt.setText(substr);
index++;
}
}
if(index==str.length())
msg.setText("您的错误率为："+form1.format(1-index/count));
}
public void KeyPressed(KeyEvent e) {}
public void KeyReleased(KeyEvent e) {}
}
[解决办法]
你有一些方法没实现：
用这个没问题：
import java.text.DecimalFormat;
import javax.swing.border.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Dazi extends JPanel implements KeyListener {
JLabel lbl1, lbl2, lbl3, lbl4, msg;
String str = "When Isaac Newton said"Every action has an equal and opposite reaction"he demonstrated he knew a lot about physics and absolutely nothing about women.";
String substr = "";
JTextArea txt;
int index = 0;
double count = 0;
DecimalFormat form1 = new DecimalFormat("0.000"); // 指定数字输出格式保留3位小数
public static void main(String args[]) {
JFrame f = new JFrame("练习英文打字");
Dazi da = new Dazi();
JPanel pane = da.init();
JPanel p = new JPanel();
f.getContentPane().add(pane);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(300, 250);
f.setVisible(true);
}
public JPanel init() {
JPanel p = new JPanel(new FlowLayout(FlowLayout.LEADING));
lbl1 = new JLabel("When Isaac Newton said"Every action");
lbl2 = new JLabel("has an equal and opposite reaction"");
lbl3 = new JLabel("he demonstrated he knew a lot about physics");
lbl4 = new JLabel("and absolutely nothing about women.");
msg = new JLabel("请输入上面的文字");
txt = new JTextArea(5, 25);
txt.setEditable(false);
txt.setLineWrap(true); // 设置自动换行
/* txt.setBorder(BorderFactory.cteateEtchedBorder(EtchedBorder.RAISED)); */
p.add(lbl1);
p.add(lbl2);
p.add(lbl3);
p.add(lbl4);
p.add(msg);
p.add(txt);
txt.addKeyListener(this);
return p;
}
public void KeyTyped(KeyEvent e) {
count++;
if (index != str.length()) {
if (String.valueOf(e.getKeyChar()).equals(
str.substring(index, index + 1))) {
substr = str.substring(0, index + 1);
txt.setText(substr);
index++;
}
}
if (index == str.length())
msg.setText("您的错误率为：" + form1.format(1 - index / count));
}
public void KeyPressed(KeyEvent e) {
}
public void KeyReleased(KeyEvent e) {
}
@Override
public void keyPressed(KeyEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void keyReleased(KeyEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void keyTyped(KeyEvent arg0) {
// TODO Auto-generated method stub
}
}
