java.swingclass testLogin extends JFrame{public testLogin(){setTitle("1234");setSize(370,450);setVisible(true);setDefaultCloseOperation(EXIT_ON_CLOSE);JLabel lab=new JLabel(new ImageIcon("1.jpg"));add(lab);JLabel lab1=new JLabel("aaa");lab.add(lab1);

java.swingclass testLogin extends JFrame{public testLogin(){setTitle("1234");setSize(370,450);setVisible(true);setDefaultCloseOperation(EXIT_ON_CLOSE);JLabel lab=new JLabel(new ImageIcon("1.jpg"));add(lab);JLabel lab1=new JLabel("aaa");lab.add(lab1);
java.swing
class testLogin extends JFrame
{
public testLogin()
{
setTitle("1234");
setSize(370,450);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
JLabel lab=new JLabel(new ImageIcon("1.jpg"));
add(lab);
JLabel lab1=new JLabel("aaa");
lab.add(lab1);
}
public static void main(String[] agrs)
{
testLogin tf=new testLogin();
}
}为什么aaa字符串显示不出来?

java.swingclass testLogin extends JFrame{public testLogin(){setTitle("1234");setSize(370,450);setVisible(true);setDefaultCloseOperation(EXIT_ON_CLOSE);JLabel lab=new JLabel(new ImageIcon("1.jpg"));add(lab);JLabel lab1=new JLabel("aaa");lab.add(lab1);
import java.awt.BorderLayout;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
class testLogin extends JFrame {
public testLogin() {
setTitle("1234");
setSize(370, 450);
setDefaultCloseOperation(EXIT_ON_CLOSE);
//JFrame中的容器默认布局管理器为Borderlayout,
//所以,在添加组件的时候要按照Borderlayout的规矩来BorderLayout.CENTER,SOUTH,WEST,EAST,NORTH
JLabel lab = new JLabel("1.jpg");//我没图片就不用设了
add(lab,BorderLayout.CENTER);
JLabel lab1 = new JLabel("aaa");
add(lab1,BorderLayout.SOUTH);
//这句话一般放到最后
setVisible(true);
}
public static void main(String[] agrs) {
testLogin tf = new testLogin();
}
}