一个JAVA问题,事件监听接口怎么不能编译,但是去掉就可以了呢?(我必须要这个监听接口,怎样解决)
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class Grade extends Applet implements ActionListener
{
//Frame
Frame f = new Frame();
BorderLayout br = new BorderLayout();
Panel P1 = new Panel();
Panel P2 = new Panel();
Panel P3 = new Panel();
Panel P4 = new Panel();
Label Ltit = new Lable("学生成绩表");
Label Lyw = new Lable("语文");
Label Lsx = new Lable("数学");
Label Lls = new Lable("历史");
Label Ldl = new Lable("地理");
Label Lyy = new Lable("英语");
Label Ladd = new Label("总分");
Label Lavg = new Label("平均分");
Label Laddss = new Label("_____");
Label Lavgss = new Label("_____");
TextField txtyw = new TxtField("",3);
TextField txtsx = new TxtField("",3);
TextField txtyy = new TxtField("",3);
TextField txtls = new TxtField("",3);
TextField txtdl = new TxtField("",3);
Button Badd = new Button("计算总分");
Button Bavg = new Button("计算平均分");
public void init()
{
f.setLayout(br);
P1.add(Ltit);
P1.setLayout(new FlowLayout());
P1.setLayout(new FlowLayout(3,4));
P1.setLayout(new FlowLayout(1,4));
P1.setLayout(new FlowLayout(1,2));
P2.add(Lyw);
P2.add(txtyw);
P2.add(Lsx);
P2.add(txtyw);
P2.add(Lyy);
P2.add(txtyy);
P2.add(Lls);
P2.add(txtls);
P2.add(Ldl);
P2.add(txtdl);
P3.add(Ladd);
P3.add(Laddss);
P3.add(Lavg);
P3.add(Lavgss);
P4.add(Badd);
P4.add(Bavg);
add(P1);
add(P2);
add(P3);
add(P4);
//
}
public void paint(Graphics g)
{
g.drawString("",20,20);
}