javascript 我无法从 onchange 事件调用两个函数
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I can't call two functions from onchange event
提问by dscxz
I have to call an ajax function as well as call an additional function to get another value by giving the above text field as the input. I want to get the return from that function. Here is the code I have used to call the 2 functions, but only the first function ajax (this) is only working, I am getting the return after calling the ajax function whereas I am not getting any return value for the second function. What am I doing wrong? Here is my code:
我必须调用 ajax 函数以及调用附加函数以通过将上述文本字段作为输入来获取另一个值。我想从那个函数中得到回报。这是我用来调用这两个函数的代码，但只有第一个函数 ajax（this）才起作用，我在调用 ajax 函数后得到了返回值，而我没有得到第二个函数的任何返回值。我究竟做错了什么？这是我的代码：
<select style="width: 305px;" name="category_id1" id="category_id1" onchange="(function(){ajax('this');return locname('this');})(this)">
My functions are:
我的职能是：
function ajax(control)
{
var loc=document.getElementById('category_id1').value;
//alert(loc);
var req;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
req=new XMLHttpRequest();
}
else
{// code for IE6, IE5
req=new ActiveXObject("Microsoft.XMLHTTP");
}
req.open("POST", "ajax.php?&loc="+loc+"", true);
req.send();
req.onreadystatechange=function(){
if(req.readyState==4&&req.status==200){
//$(".error").hide();
result=req.responseText
alert(result);
var items = JSON.parse(result);
//alert(items.length)
var html = '<option value="">Select</option>';
for ( var i = 0; i < items.length; i++ ) {
html += "<option value='" + items[ i ] + "'>" + items[ i ] + "</option>"
}
document.getElementById("Ultra").innerHTML = html;
}
}
}
function locname(control)
{
var locName=control.value;
//alert(locName)
var json = <?php echo $response ?>;
var orgName=document.getElementById("category_id").value;
//alert(json);
var html="<option>Select</option>";
var locations;
//alert(json.length);
for(var i=0; i<json.length; i++)
{
var item = json[i].name;
//alert(item);
if(orgName===item){
//alert(item)
locations=json[i].location;
for(var j=0;j<locations.length;j++){
var location=locations[j].name;
//alert(locName)
if(locName===location)
{
//alert(locName);
var buildings=locations[j].building
//alert(buildings)
for(var k=0;k<buildings.length;k++)
{
var building=buildings[k];
//alert(building);
html=html+"<option value='"+building+"'>"+building+"</option>";
}
}
}
}
}
document.getElementById("category_id2").innerHTML=html;
}
回答by hsz
Just try with:
只需尝试：
onchange="ajax(this);locname(this);"
回答by Barmar
Don't put quotes around this. That passes the literal string instead of the value of the variable this.
不要在 周围加上引号this。它传递的是文字字符串而不是变量的值this。
