Question

下面这段java代码执行后结果为什么只显示背景图片而不显示控件？

import javax.swing.*;

import java.awt.*;

import java.util.*;

public class Test2 {

JFrame frame;

JTextField field;

JPanel panel;

JButton button;

JLabel label;

public void myframe(){

frame=new JFrame("Test");

frame.setSize(300,300);

frame.setVisible(true);

Container c2=frame.getLayeredPane();

c2.setLayout(new BorderLayout());

c2.add(new MyComponent());

JPanel c=(JPanel)frame.getContentPane();

c.setOpaque(false);

c.setLayout(new FlowLayout());

c.add(field=new JTextField(10));

c.add(button=new JButton("ok"));

}

public static void main(String[] agrs){

new Test2().myframe();

}

}

class MyComponent extends JComponent{

public void paintComponent(Graphics g){

Image image=new ImageIcon("c://first.jpg").getImage();

g.drawImage(image,0,0,300,300,null);

}

}

Answer 1

Image image=new ImageIcon("c://first.jpg").getImage();

最好 图片，先加载好

追问

为什么呢?

是不是加载图片会卡，用新线程还会这样吗