document.getElementById(somevar)不起作用

时间:2010-02-09 13:20:33

标签: javascript ajax getelementbyid

我有以下代码,但getElementById(setID)对我不起作用, 我知道它会捕获id,因为alert(setID)正在工作。

任何想法?

function getdata(file, aID){
req = xmlHttpRequestHandler.createXmlHttpRequest();
req.onreadystatechange = Response;
req.open("GET", file, true);
req.send(null);
setID = aID;
}

function Response() { 
    var ready, status;
    try {
        ready = req.readyState;
        status = req.status;
    }
    catch(e) {}
    if (ready == 4 && status == 200) {
          document.getElementById("data").innerHTML = req.responseText;
    }

   document.getElementById(setID).className = "someclass";
}


<div class="msg" id="someid">
<a href="javascript:getdata('data.php', 'someid')">somelink</a>
</div>

3 个答案:

答案 0 :(得分:4)

将setID用作全局变量或将其传递给回调函数。

function getdata(file, aID)
{
    req = xmlHttpRequestHandler.createXmlHttpRequest();
    setID = aID;
    req.onreadystatechange = function() {Response(setID);};
    req.open("GET", file, true);
    req.send(null);
}

function Response(setID) 

答案 1 :(得分:1)

如果

document.getElementById("data")

不起作用,在99%的情况下,这有以下原因之一:

  • 该元素不再存在或存在

  • 有多个ID为data

  • 的元素

当AJAX调用引入的HTML代码也包含具有相同ID的元素时,通常会发生这种情况。

答案 2 :(得分:1)

您是否将setID变量设为全局变量?如果没有,那么试试这个:

var setID = null; // we set this here because it is referenced in functions

function getdata(file, aID){
req = xmlHttpRequestHandler.createXmlHttpRequest();
req.onreadystatechange = Response;
req.open("GET", file, true);
req.send(null);
setID = aID;
}

function Response() { 
    var ready, status;
    try {
        ready = req.readyState;
        status = req.status;
    }
    catch(e) {}
    if (ready == 4 && status == 200) {
          document.getElementById("data").innerHTML = req.responseText;
    }

   document.getElementById(setID).className = "someclass";
}