import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Image1 {
    
    public void init1(){
        
    
    Frame f =new Frame("学生考评系统");
    Button b1=new Button("教师");
    Button b2=new Button("学生");
    Button b3=new Button("退出");
    
    b2.addActionListener((ActionListener) new StudentListener());
    
    Label l=new Label("欢迎来到学生考评系统，请选择用户");
    f.setLayout(new FlowLayout(FlowLayout.LEFT,20,5));
    
    f.add(l);
    f.add(b1);
    f.add(b2);
    f.add(b3);
    f.setBounds(470,230,250,120);
    
    f.pack();
    f.setVisible(true);
    
    
    }
    
    class StudentListener implements ActionListener
    {

        @Override
        public void actionPerformed(ActionEvent e) 
        {
            
            new Image2().init2();
        }
        
    }
    
    class Image2 {
    
        public void init2()
        {
            Frame f=new Frame("学生用户");
            Label l=new Label("请输入学号");
            TextArea t=new TextArea();
            f.setLayout(new FlowLayout(FlowLayout.LEFT,20,5));
            
            f.add(l);
            f.add(t);
            f.pack();
            
        }
        
    }
    public static void main(String[] args)
    {
        new Image1().init1();
        
    }
    
}