java为什么运行之后控件不出来,而最大化之后才出来

[peterpei_]

我是初学者，我编了一个程序，可是运行之后，那些label，textfield，combobox等控件都不出来，以最大化，就出来了。

那是为什么呢。


小破程序如下，希望那位大哥指点一下


import javax.swing.*;
import java.awt.*;


class FrameTest extends JFrame
{
public FrameTest()
{
super("选修课");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
setSize(800,800);

}
}


class PanelTest extends FrameTest
{
JPanel panelObj;
public PanelTest()
{
panelObj=new JPanel();
getContentPane().add(panelObj);

}
}


class ComponentTest extends PanelTest
{
JLabel labelnumber;
JLabel labelname;

JButton button1;
JButton button2;

JTextField textname;
JTextField textnumber;
JLabel labelcourse;
JLabel labelselected;
JComboBox comboclass;
JList listclass;


public ComponentTest()
{

button1=new JButton("fuck");
button2=new JButton("fuck");
labelname=new JLabel("姓名：");
textname=new JTextField(25);

labelnumber=new JLabel("学号：");
textnumber=new JTextField(25);

labelcourse=new JLabel("修课: ");
labelselected=new JLabel("课程: ");

String strclass[]={"java","vb","c++","jsp"};
comboclass=new JComboBox(strclass);
//String strclass1[]={"java","vb","c++","jsp"};
listclass=new JList();

panelObj.add(labelname);
panelObj.add(textname);
panelObj.add(labelnumber);
panelObj.add(textnumber);
panelObj.add(labelcourse);
panelObj.add(labelselected);
panelObj.add(button1);
panelObj.add(button2);

panelObj.add(comboclass);
panelObj.add(listclass);
}
}

class layoutmanagertest extends ComponentTest
{
GridBagLayout gbLayoutObj;
GridBagConstraints gbcObj;

public layoutmanagertest()
{
gbLayoutObj=new GridBagLayout();
gbcObj=new GridBagConstraints();
panelObj.setLayout(gbLayoutObj);
gbcObj.anchor=GridBagConstraints.EAST;
gbcObj.gridx=1;
gbcObj.gridy=1;
gbLayoutObj.setConstraints(labelname,gbcObj);
gbcObj.gridy=2;
gbLayoutObj.setConstraints(labelnumber, gbcObj);
gbcObj.gridy=3;
gbLayoutObj.setConstraints(labelcourse, gbcObj);
gbcObj.gridy=4;
gbLayoutObj.setConstraints(labelselected, gbcObj);
gbcObj.anchor=GridBagConstraints.WEST;

gbcObj.gridx=2;
gbcObj.gridy=1;
gbLayoutObj.setConstraints(textname, gbcObj);
gbcObj.gridy=2;
gbLayoutObj.setConstraints(textnumber, gbcObj);
gbcObj.gridy=3;
gbLayoutObj.setConstraints(comboclass, gbcObj);
gbcObj.gridy=4;
gbLayoutObj.setConstraints(listclass, gbcObj);


gbcObj.gridy=5;
gbLayoutObj.setConstraints(button1,gbcObj);
gbcObj.gridx=1;
gbcObj.anchor=GridBagConstraints.EAST;
gbLayoutObj.setConstraints(button2,gbcObj);



}

}
public class xuanxiuke
{
public static void main(String[] args)
{
new layoutmanagertest ();
}
}

[cursor_wang]

你把上面的setVisible(true); setSize(800,800);注释掉，把main()改了就可以了

public   class   xuanxiuke 
{ 
    public   static   void   main(String[]   args) 
    { 
    	layoutmanagertest test=new   layoutmanagertest   (); 
    	test.setVisible(true);
    	test.setSize(800,800);
    } 
}

[peterpei_]

谢谢了，可是那是为什么呢

[cursor_wang]

明明我回复了，怎么上面写了（问题点数：10 回复次数：0）嘿！可能又是bug，无语．
继续回复：你把上面的注释掉setVisible(true); setSize(800,800);在main()中加就可以了．

public   class   xuanxiuke 
{ 
    public   static   void   main(String[]   args) 
    { 
        layoutmanagertest　test=new   layoutmanagertest   (); 
　　　　　test.setVisible(true);
　　　　　test.setSize(800,800);
    } 
}