java Event小问题

Question

package extend;
import java.awt.event.WindowAdapter;
import java.awt.*;
import java.awt.event.WindowEvent;
import java.awt.event.*;
public class EventManagerDemo  {
public static void main(String args[]){
final Frame f=new Frame("Test");
Button b=new Button("Press ME");
b.addActionListener(new ButtonHandler());
f.setLayout(new FlowLayout());
f.add(b);
f.setSize(200,100);
f.addWindowListener(new WindowAdapter(){
public void WindowClosing(WindowEvent evt){
f.setVisible(true);
f.dispose();
System.exit(0);

}

});
f.setVisible(true);

}
 
}
    class  ButtonHandler  implements ActionListener{
 public void actionperformed(ActionEvent e){
 System.out.print("已经捕获");
 }
}
 对于类ButtonHandler我已经重写了 接口的方法 还是报错  要我实现抽象方法 怎么办呢？

Answer 1

你最后的 ButtonHandler的方法名称大小写有问题， actionperformed改成actionPerformed就OK
import java.awt.event.WindowAdapter;
import java.awt.*;
import java.awt.event.WindowEvent;
import java.awt.event.*;
public class EventManagerDemo {
    public static void main(String args[]){
        final Frame f=new Frame("Test");
        Button b=new Button("Press ME");
        b.addActionListener(new ButtonHandler());
        f.setLayout(new FlowLayout());
        f.add(b);
        f.setSize(200,100);
        f.addWindowListener(new WindowAdapter(){
            public void WindowClosing(WindowEvent evt){
                f.setVisible(true);
                f.dispose();
                System.exit(0);            }        });
        f.setVisible(true);    }}
class ButtonHandler  implements ActionListener{
    
    public void actionPerformed(ActionEvent e){
        System.out.print("已经捕获");
    }
}

Answer 2

拼写错误            public void WindowClosing(WindowEvent evt){技巧： 
重写的方法加上 ＠Override