请教：在jsp页面中下拉列表框不用提交按钮如何将选中项传给后台的servlet

下拉列表没有selectchange之类的事件吗？

解决方案 »

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有的，用了这个函数之后表单是自动提交了，但是ztree中没有显示相应的内容，这是我的代码
<html>
<HEAD>
  <TITLE> 评估 </TITLE>

  <link rel="stylesheet" href="css/zTreeStyle/zTreeStyle.css" type="text/css">

<script type="text/javascript" src="js/jquery-1.4.4.min.js"></script>
<script type="text/javascript" src="js/jquery.ztree.core-3.5.js"></script>
<SCRIPT type="text/javascript" >
var zTree;
var demoIframe;var setting = {
view: {
dblClickExpand: false,
showLine: true,
selectedMulti: false
},
data: {
simpleData: {
enable:true,
idKey: "id",
pIdKey: "pId",
rootPId: ""
}
},
callback: {
beforeClick: function(treeId, treeNode) {
var zTree = $.fn.zTree.getZTreeObj("tree");
if (treeNode.isParent) {
zTree.expandNode(treeNode);
return false;
} else {
demoIframe.attr("src",treeNode.file + ".html");
return true;
}
}
}
};
function DoOnchange(){
   document.yxNameForm.submit();
}
var zNodes;
$(document).ready(function(){
$.ajaxSetup({async:false});
$.getJSON("JDataServlet",function(data){   /*通过servlet将后台取到的值传给ztree，这个地方是不是需要将select选中的值传给servlet，但在servlet中是可以直接用request.getParameter("yxNameSelect")来取值，所以这里感觉不需要参数，如果需要参数的，那么怎么带参数，请指教*/
// alert("jsonData is:"+data);
zNodes = data;
});
var t = $("#tree");
t = $.fn.zTree.init(t, setting, zNodes);
demoIframe = $("#testIframe");
demoIframe.bind("load", loadReady);
var zTree = $.fn.zTree.getZTreeObj("tree");
zTree.selectNode(zTree.getNodeByParam("id", 101));
});function loadReady() {
var bodyH = demoIframe.contents().find("body").get(0).scrollHeight,
htmlH = demoIframe.contents().find("html").get(0).scrollHeight,
maxH = Math.max(bodyH, htmlH), minH = Math.min(bodyH, htmlH),
h = demoIframe.height() >= maxH ? minH:maxH ;
if (h < 530) h = 530;
demoIframe.height(h);
}
  </SCRIPT>
</HEAD><BODY>
<jsp:useBean id="manage" class="dbUtil.DBManager" scope="page"></jsp:useBean>
<form name="yxNameForm" method="post" action="JDataServlet">
<TABLE width="278" height=347 border=0 align=left>
    <TR>
        <TD height="29" align=left valign=middle style="BORDER-RIGHT: #999999 1px dashed">请选择类别名</TD>
  </TR>
   <TR>
        <td height="40" align=left valign=middle style="BORDER-RIGHT: #999999 1px dashed">

          类别名称：
          <select name="yxNameSelect" id="yxNameSelect"  onChange="DoOnchange()">
            <%
    Collection col = manage.getYXList();
Iterator<YXXDBean> it = col.iterator();
    while(it.hasNext()){
YXXDBean yx = it.next();
  %>
            <option value=<%=yx.getYxmc()%>><%=yx.getYxmc()%></option>
            <%}%>
          </select>
          <input  type="submit" name="submit" value="go">

        </td>
</TR>
<TR>
<TD align=left valign=top bgcolor="#deedf7" style="BORDER-RIGHT: #999999 1px dashed"><ul id="tree" class="ztree" style="width:260px; overflow:auto;">
    </ul></TD>
<TD width=53 align=left valign=top></TD>
</TR>
</TABLE>
</form>
</BODY>
</HTML>
form提交之后，返回的是什么？在ajax的回调函数里处理数据就行了啊