setbackground为什么没用呢？


package bornthisway;

import java.awt.*;

import javax.swing.*;

public class BornThisWay extends JFrame {

public Container container = null;

JLabel soil=new JLabel();



public BornThisWay() {

this.setTitle("test");

this.setSize(810, 510);

setResizable(false);

setLocationRelativeTo(null);

container = this.getContentPane();

container.setLayout(null);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setVisible(true);

soil.setBackground(Color.DARK_GRAY);

soil.setText("0,250==============================================================================================================");

container.add(soil);

soil.setSize(810, 10);

soil.setLocation(0, 350);



}

public static void main(String[] args) {

new BornThisWay();

}

}



我设置了soil背景色为灰色，可是运行没显示，为什么呢？


[解决办法]
soil.setBackground(Color.DARK_GRAY);前先，

Java code

soil.setOpaque(true);