运行后窗体不显示内容,改变窗口大小就显示内容,为啥?
豆腐花发 2016-06-23 08:52:22 package Number;
import java.awt.*;
import javax.swing.*;
import java.net.*;
import java.util.Vector;
import java.awt.event.*;
public class ZuoYe extends JFrame{
//static final long serialVersionUID = 1L;
String arr[] = {"列表1","列表2","列表3","列表4"};
int index = 0;
public ZuoYe(){
Container con = getContentPane();
setLayout(new BorderLayout());
setVisible(true);
setSize(500,500);
setTitle("边界布局");
con.setBackground(Color.green);
JComboBox<String> jcomBox = new JComboBox<>();
jcomBox.addItem("红色");
jcomBox.addItem("橙色");
jcomBox.addItem("黄色");
jcomBox.addItem("绿色");
con.add(jcomBox, BorderLayout.NORTH);
con.add(BorderLayout.NORTH,jcomBox);
JPanel jpanel = new JPanel();
JCheckBox jcheckBox1 = new JCheckBox("男");
JCheckBox jcheckBox2 = new JCheckBox("女");
jpanel.add(jcheckBox1);
jpanel.add(jcheckBox2);
con.add(jpanel,BorderLayout.CENTER);
JButton jb1 = new JButton("添加");
JButton jb2 = new JButton("取消");
JPanel jpanel2 = new JPanel();
jpanel2.add(jb1);
jpanel2.add(jb2);
con.add(jpanel2,BorderLayout.SOUTH);
jb1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
if(index < arr.length){
jcomBox.addItem(arr[index++]);
}
}
});
}
public static void main(String[] args) {
// TODO 自动生成的方法存根
new ZuoYe();
}
}
大神帮忙看下。