javascript jquery无法读取未定义的属性“getAttribute”
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jquery Cannot read property 'getAttribute' of undefined
提问by zoomynn
The javascript I'm using works completely fine in firefox and ie but has this error when run on chrome and safari. I'm not entirely sure why it's failing.
我使用的 javascript 在 firefox 和 ie 中完全正常，但在 chrome 和 safari 上运行时出现此错误。我不完全确定它为什么失败。
var response = asyncResult.value;
if (window.DOMParser) {
var parser = new DOMParser();
xmlDoc = parser.parseFromString(response, "text/xml");
}
else
{
xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.async = false;
xmlDoc.loadXML(response);
}
console.log(xmlDoc);
var changeKey = xmlDoc.getElementsById("t:ItemId")[0].getAttribute("ChangeKey");
The console shows this message but outputs the xmlDoc just fine when I have it set to console.log()
控制台显示此消息，但当我将其设置为 console.log() 时输出 xmlDoc 就好了
Uncaught TypeError: Cannot read property 'getAttribute' of undefined r.js
soapToGetItemDataCallback r.js
r.onreadystatechange outlookwebapp-15.js:21
$h.EwsRequest.x_1 outlookwebapp-15.js:21
(anonymous function) outlookwebapp-15.js:21
回答by Wilfredo P
The problem is that you are trying to get the element by ID and using [0], I guess you wanna getElementsByTagNamebecause that the result is undefined, the code should be:
问题是您正在尝试通过 ID 获取元素并使用[0]，我猜您想要getElementsByTagName因为结果未定义，代码应该是：
var changeKey = xmlDoc.getElementsById("t:ItemId").getAttribute("ChangeKey");
Or if "t:ItemId"is a collection:
或者如果"t:ItemId"是一个集合：
var changeKey = xmlDoc.getElementsByTagName("t:ItemId")[0].getAttribute("ChangeKey");
