Question

java,swing中设置setlayout为null的时候，有些组件无法显示

import java.awt.*;
import javax.swing.*;
public class JScrollPaneTest extends JFrame{
public JScrollPaneTest(){
super();
Container c = getContentPane();
JTextArea ta = new JTextArea(100,10);
ta.setBounds(10, 10, 100, 100);
JScrollPane sp = new JScrollPane(ta);
c.add(sp);
//c.add(ta);
setLayout(null);
}
public static void main(String args[]) {
JFrame jf = new JScrollPaneTest();
jf.setSize(400, 400);
jf.setVisible(true);
}
}
如题，JScrollPane 无法显示，还有JLabel也无法显示

Answer 1

JScrollPane sp = new JScrollPane(ta);
sp.setBounds(10, 10, 100, 100);