dropdownlist jquery ddl.change()似乎在发生更改之前触发
我有三个级联下拉列表 DllillnessType、DllillnessSubtype和DllInfectivityAgent 最初,仅显示DDillnessType。更改时,DDillnessSubtype将填充json数据并使其可见。到目前为止,一切顺利 接下来,当用户从DDillnessSubtype中选择一个值时,将在DDillnessSutType更改事件处理程序中为DDLLInfectivityAgent运行一个类似的过程。但是,在以下代码中,$(this).val()始终显示为“未定义”,即使用户选择了现有值:dropdownlist jquery ddl.change()似乎在发生更改之前触发,jquery,asp.net-mvc,drop-down-menu,Jquery,Asp.net Mvc,Drop Down Menu,我有三个级联下拉列表 DllillnessType、DllillnessSubtype和DllInfectivityAgent 最初,仅显示DDillnessType。更改时,DDillnessSubtype将填充json数据并使其可见。到目前为止,一切顺利 接下来,当用户从DDillnessSubtype中选择一个值时,将在DDillnessSutType更改事件处理程序中为DDLLInfectivityAgent运行一个类似的过程。但是,在以下代码中,$(this).val()始终显示为“未
$("#ddlIllnessSubType").change(function() {
var selection = $(this).val();
// go and get Json based on the value of selection.
// Doesn't work cos selection == 'undefined'
var url = "/IllnessDetail/CascadedDdlInfectiousAgent/" + selection;
getJSON(url, function(data) {...});
...
});
value="undefined"
为什么选择==“未定义”
提前谢谢
安德鲁
PS:完整的jQuery和HTML如下所示:
完整的jQuery代码是:
<script type="text/javascript">
$('document').ready(function() {
var pEst = $("#pEncephalitisSubType");
var pIa = $("#pInfectiousAgent");
var ddlEst = $("#IdEncephalitisSubType");
var ddlIa = $("#IdInfectiousAgent");
$('#SubTypeContainer').hide();
pEst.hide();
pIa.hide();
// debugger
$('select').each(function() {
$(this).val(""); //alert($(this).val());
});
// Change Event Handler
$("#IdEncephalitisType").change(function() {
var selection = $(this).val();
pEst.fadeOut('slow');
pIa.fadeOut('slow');
ddlEst.val("");
ddlIa.val("");
if (selection == 0) {
$('#SubTypeContainer').fadeOut('slow');
}
else {
var url = "/Members/IllnessDetail/CascadedDdlSubType/" + selection;
AjaxEncephalitisSubTypes(url);
}
});
// Change Event Handler
$("#IdEncephalitisSubType").change(function() {
var selection = $(this).val();
debugger
pIa.fadeOut('slow');
ddlIa.val("");
if (selection != "") {
if (($("#IdEncephalitisType").val() == 1) && ((selection == 1) || (selection == 2))) {
var url = "/Members/IllnessDetail/CascadedDdlInfectiousAgent/" + selection;
AjaxInfectiousAgents(url);
}
}
});
function AjaxEncephalitisSubTypes(url) {
$('#SubTypeContainer').fadeOut('slow');
$.getJSON(url, null, function(json) {
ddlEst.empty();
ddlIa.empty();
PrependDdlDefaults(ddlEst);
var i = 0;
$.each(json, function(index, optionData) {
ddlEst.append("<option value='"
+ optionData.EncephalitisSubTypeId
+ "'>" + optionData.Name
+ "</option>");
i++;
});
$('#SubTypeContainer').fadeIn('slow');
ddlEst.val("");
pEst.fadeIn('slow');
});
}
function AjaxInfectiousAgents(url) {
$('#SubTypeContainer').fadeOut('slow');
$.getJSON(url, null, function(data) {
var i = 0;
ddlIa.empty();
PrependDdlDefaults(ddlIa);
$.each(data, function(index, optionData) {
ddlIa.append(
"<option value='"
+ optionData.InfectiousAgentId
+ "'>" + optionData.Name
+ "</option>");
i++;
});
});
ddlIa.val("");
$('#SubTypeContainer').fadeIn('slow');
pIa.fadeIn('slow');
}
function PrependDdlDefaults(ddl) {
ddl.prepend(
"<option value='"
+ ""
+ "'><i>" + " --- Please choose... --- "
+ "</i></option>");
}
});
</script>
<fieldset>
<legend>The Illness</legend>
<p>
According to your input, different drop down lists will appear, specialised to only
show the options that apply.
</p>
<p>
<label for="IdEncephalitisType">
Type Of Encephalitis:</label>
<%= Html.DropDownList("IdEncephalitisType", Model.EncephalitisTypes)%>
<%= Html.ValidationMessage("IdEncephalitisType", "*") %>
</p>
<div id="SubTypeContainer" style="margin-left:10px;border: solid 1px #ccc; background: #efefef;">
<p class="highlight" id="lblSubTypeContainer" style="font-weight:bold;color:#c00;">
Extra Information regarding the Illness:</p>
<p id="pEncephalitisSubType">
<label id="lblEncephalitisSubType" for="IdEncephalitisSubType">
Sub Type of Encephalitis:</label>
<%= Html.DropDownList("IdEncephalitisSubType", Model.EncephalitisSubTypes)%>
<%= Html.ValidationMessage("IdEncephalitisSubType", "*") %>
</p>
<p id="pInfectiousAgent">
<label id="lblInfectiousAgent" for="IdInfectiousAgent">
Infectious Agent:</label>
<%= Html.DropDownList("IdInfectiousAgent", Model.InfectiousAgents) %>
<%= Html.ValidationMessage("IdInfectiousAgent", "*") %>
</p>
</div>
</fieldset>
$('document').ready(函数(){
var pEst=$(“#pEncephalitisSubType”);
var pIa=$(“PINFECIOUSAGENT”);
var ddlEst=$(“#idencephalitisubtype”);
变量ddlIa=$(“#IDifactiousAgent”);
$(“#子容器”).hide();
pEst.hide();
pIa.hide();
//调试器
$('select')。每个(函数(){
$(this.val(“”;//警报($(this.val());
});
//更改事件处理程序
$(“#idencephalitype”).change(函数(){
var selection=$(this.val();
害虫消失(“缓慢”);
pIa.fadeOut(“慢”);
ddlEst.val(“”);
ddlIa.val(“”);
如果(选择==0){
$(“#子容器”).fadeOut('slow');
}
否则{
var url=“/Members/IllnessDetail/cascadedldsubtype/”+选择;
ajax病毒亚型(url);
}
});
//更改事件处理程序
$(“#idencephalitisubtype”).change(函数(){
var selection=$(this.val();
调试器
pIa.fadeOut(“慢”);
ddlIa.val(“”);
如果(选择!=“”){
if($(“#idencephalitype”).val()=1)和&((selection==1)| |(selection==2))){
var url=“/Members/illnessdail/cascadeddlinfectiviousagent/”+选择;
Ajaxinfective代理(url);
}
}
});
函数子类型(url){
$(“#子容器”).fadeOut('slow');
$.getJSON(url,null,函数(json){
ddlEst.empty();
ddlIa.empty();
prependdldldlddefaults(ddlEst);
var i=0;
$.each(json、函数(索引、optionData){
ddlEst.append(“+optionData.Name
+ "");
i++;
});
$(“#子容器”).fadeIn('slow');
ddlEst.val(“”);
pEst.fadeIn(“慢”);
});
}
函数AjaxInfectiousAgents(url){
$(“#子容器”).fadeOut('slow');
$.getJSON(url,null,函数(数据){
var i=0;
ddlIa.empty();
PrependdlDefaults(ddlIa);
$.each(数据、函数(索引、选项数据){
ddlIa.append(
“”+optionData.Name
+ "");
i++;
});
});
ddlIa.val(“”);
$(“#子容器”).fadeIn('slow');
pIa.fadeIn(“慢”);
}
函数PrependdlDefaults(ddl){
ddl.prepend(
“+”---请选择…--”
+ "");
}
});
疾病
根据您的输入,将出现不同的下拉列表,专门针对
显示适用的选项。
脑炎类型:
脑炎亚型:
传染源:
不需要显示控制器,因为交付的json是正确的。就像在中一样,我已经测试了它,得到的渲染是正确的。破解了它
问题出在json回调中:
$.each(json, function(index, optionData) { ddlEst.append("<option value='" + optionData.Id + "'>" + optionData.Name + "</option>"); i++; });
$.each(json, function(index, optionData) {
ddlEst.append("<option value='"
+ optionData.Id
+ "'>" + optionData.Name
+ "</option>");
i++;
});
aaaaaaaa rrrrrrr ggggggjjhhhhh