修改如下:
//Construct the application
public MyMouse() {
f.addMouseListener(new MEntered());
}
class MEntered extends MouseAdapter{
public void mouseEntered(MouseEvent e){
f.setBackground(Color.blue);
}
}
//Construct the application
public MyMouse() {
f.addMouseListener(new MEntered());
}
class MEntered extends MouseAdapter{
public void mouseEntered(MouseEvent e){
f.setBackground(Color.blue);
}
}
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;class MyMouse {
Frame f; //Construct the application
public MyMouse() {
f=new Frame("Mouse Example");
f.addMouseListener(new MEntered());
}
class MEntered extends MouseAdapter{
public void mouseEntered(MouseEvent e){
f.setBackground(Color.blue);
}
}
//Main method
public static void main(String[] args) {
try {
MyMouse app=new MyMouse();
app.f.setBounds(10,10,100,200);
app.f.setBackground(Color.green);
app.f.setVisible(true);
}
catch(Exception e) {
e.printStackTrace();
}
}
}