一个从数据库读数据填充下拉框的问题

Question

在JTabbedPane上有两个Panel,每个都有四个下拉框,每个下拉框的数据都是从数据库读取的.当选择
JTabbedPane时发生改变事件,来改变下拉框的值,但是当我改变的时候它的值并没有改变,而是原来读取的值,是怎么回事呢?
 String []chooseName=new String[40];
    try {
        con = pp.getConnection();
        stmt=con.createStatement();
        
        if(CHANGE==0)
        {
            QUERYSTR="select cField  from codetable where cTablename='custom'";
            rs= stmt.executeQuery(QUERYSTR);
            while(rs.next())
           {
            chooseName[value]=String.valueOf(rs.getString("cField"));
             value++;                     
           }
        }
        if(CHANGE==1)
       {
           QUERYSTR="select cField  from codetable where cTablename='INSIDE'";
           rs= stmt.executeQuery(QUERYSTR);
           while(rs.next())
           {
          chooseName[value]=String.valueOf(rs.getString("cField"));
          value++;                     
          }
          CustomerChoose1 = new JComboBox(chooseName);
          CustomerChoose2 = new JComboBox(chooseName);
          CustomerChoose3 = new JComboBox(chooseName);
          CustomerChoose4 = new JComboBox(chooseName);

Answer 1

我把第一个Panel中的所有下拉框在事件发生的时候移到了Panel中，也就是两个Panel共用一套下拉框，在事件发生的时候我把装下拉框的Panel加入所改变的Panel

Answer 2

比如说我有四个下拉框，每个下拉框中的内容是从数据库中读取出来的，给了一个字符串数组，当我改变JTabbedPane中的Panel的时候，下拉框开始填充其他的值，也是把这些值添加到数组中，然后加近来的，也就是改变选择JTabbedPane时候就改变了SQL语句，也就改变了添入下拉框的值，但是当我运行的时候它把值填入下拉框中，当我改变JTabbedPane的时候下拉框的值没有变，还是原来运行时候的数据

Answer 3

public void stateChanged(ChangeEvent e) {
  CHANGE=jTabbedPane1.getSelectedIndex();
    if(CHANGE==0)
  {  chooseData();
      p1.add(panelGUI);//把组键加到p1上       System.out.println(QUERYSTR);
  }
    if(CHANGE==1)
    {
      chooseData();
      p2.add(panelGUI);
      System.out.println(QUERYSTR);
   }
    if(CHANGE==2)
   {
     chooseData();
     p3.add(panelGUI);
   }
   if(CHANGE==3)
     {
       chooseData();
       p4.add(panelGUI);
     }     if(CHANGE==4)
   {
     chooseData();
      p5.add(panelGUI);
   }
  }
public void  chooseData()
{
  int value=0;
   String []chooseName=new String[40];
    try {
        con = pp.getConnection();
        stmt=con.createStatement();        if(CHANGE==0)
        {
            QUERYSTR="select cField  from codetable where cTablename='custom'";
            rs= stmt.executeQuery(QUERYSTR);
            while(rs.next())
           {
            chooseName[value]=String.valueOf(rs.getString("cField"));
             value++;
           }
        }
        if(CHANGE==1)
       {
           QUERYSTR="select cField  from codetable where cTablename='INSIDE'";
           rs= stmt.executeQuery(QUERYSTR);
           while(rs.next())
           {
          chooseName[value]=String.valueOf(rs.getString("cField"));
          value++;
          }
       }
       if(CHANGE==2)
      {
        QUERYSTR="select cField  from codetable where cTablename='Detach'";
        rs= stmt.executeQuery(QUERYSTR);
        while(rs.next())
        {
          chooseName[value]=String.valueOf(rs.getString("cField"));
          value++;
        }
      }
      if(CHANGE==3)
      {
        QUERYSTR="select cField  from codetable where cTablename='TOUCH'";
        rs= stmt.executeQuery(QUERYSTR);
        while(rs.next())
        {
          chooseName[value]=String.valueOf(rs.getString("cField"));
          value++;
        }
      }
      if(CHANGE==4)
      {
        QUERYSTR="select cField  from codetable where cTablename='Customer'";
        rs= stmt.executeQuery(QUERYSTR);
        while(rs.next())
        {
          chooseName[value]=String.valueOf(rs.getString("cField"));
          value++;
        }
      }          CustomerChoose1 = new JComboBox(chooseName);
          CustomerChoose2 = new JComboBox(chooseName);
          CustomerChoose3 = new JComboBox(chooseName);
          CustomerChoose4 = new JComboBox(chooseName);
          CustomerChoose5 = new JComboBox(chooseName);
          CustomerChoose5.setBounds(new Rectangle(90, 3, 141, 24));
          CustomerChoose2.setBounds(new Rectangle(90, 2, 141, 24));
          CustomerChoose1.setBounds(new Rectangle(90, 3, 141, 24));
          CustomerChoose4.setBounds(new Rectangle(90, 3, 141, 24));
          CustomerChoose3.setBounds(new Rectangle(90, 3, 141, 24));
        }
      catch (SQLException ex1) {
      }
}

Answer 4

第一个CHANGE的范围是否在CHOOSEDATA可控范围内，也就是说STATECHANGED改变后，choosedata是否能感应到，
第二，customerchoose1,customerchoose2,customerchoose3,customerchoose4..
重新引用别的对象后，包含那些对象的面版，比如你的“panelGUI”必须重新清空一下内容，再重新导入你的customerchoose1,customerchoose2,customerchoose3,customerchoose4，否则包含还是原来的Jcombox