jspjs实现二级联动菜单.docVIP

jsp+js实现的二级联动菜单 以前看朋友写二级联动菜单思路都是先取得大类的数据,当选择大类后用url传值的方式传给页面一个值,然后根据这个值从数据库取出相应的小类的值.一直觉得这个思路虽然直接,但好像要频繁的读取数据库,而且如果表单里有多个选项的话,有时候似乎并不方便.到网上找了静态的javascript联动菜单.改了改后,感觉还可以: ? ??? 原javascript代码: ???????? SCRIPT language=javascript !-- var subcat = new Array(); subcat[0] = new Array(no,大类,12)subcat[1] = new Array(pinp,楼宇包装,louy) subcat[2] = new Array(pinp,会场布置,meet)subcat[3] = new Array(pinp,开日庆典,kai)subcat[4] = new Array(pinp,婚庆礼仪,hun)!--changeselect1(5)--function changeselect1(locationid) { ?form1.smallclass.length = 0; //初始化下拉列表 清空下拉数据 ?for (i=0; isubcat.length; i++) //legth=20 ?{ ??if (subcat[i][0] == locationid) //[0] [1] 第一列 第二列 subcat[i][2]为s2的value值??{???form1.smallclass.options[form1.smallclass.length] = new Option(subcat[i][1], subcat[i][2]);//建立option ??} ?} } //-- /SCRIPT ? ?一级分类：SELECT onChange=changeselect1(this.options[this.selectedIndex].value) name=bigclass ???????? OPTION=请选择=/OPTION? ???????? OPTION value=pinp品牌策划/OPTION???????? OPTION value=design设计印刷/OPTION???????? OPTION value=media户外传媒/OPTION???????? OPTION value=jiag工艺加工/OPTION/SELECT???????? 二级分类：???????? SELECT id=smallclass name=smallclass ???????? /SELECT ? ? ???? 数据库中大类:bigclass:pid,pName ?????????????????????小类:smallclass:psid,pscName,pid 我的思路是:从数据库中取出大类与小类的值,填充在javascript里,这样只须读取一次数据,剩下的事就交给js去处理了. 定义两个ResultSet 对象rssml rsbig.上面JS代码更改后, ? SCRIPT language=javascript !-- var subcat = new Array();%? int h=0;??? while(rssml.next())??? { % ????? ????? subcat[%=h%] = new Array(%= rssml.getInt(pcid)%,%= rssml.getString(pscName) %,%= rssml.getInt(psid) %);???? %h++; } %!--changeselect1(5)--function changeselect1(locationid) { ?form1.smallclass.length = 0; //初始化下拉列表 清空下拉数据 ?for (i=0; isubcat.length; i++) //legth=20 ?{ ??if (subcat[i][0] == locationid) //[0] [1] 第一列 第二列 subcat[i][2]为s2的value值??{???form1.smallclass.options[form1.smallclass.length] = new Option(subcat[i][1], subcat[i][2]);//建立option ??} ?} } //-- /SCRIPT ? select name=bigclass onChan