jQuery：this.attr() 不是函数？
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jQuery: this.attr() not a function?
提问by chaoskreator
I'm not quite sure if I'm not using this in the correct scope or what, but I have a script that basically captures a link click and causes the page to fade out before going to the linked page. However, if the link is a JavaScript onclick, the script fails.
我不太确定我是否没有在正确的范围内使用它或什么，但我有一个脚本，它基本上捕获链接点击并导致页面在转到链接页面之前淡出。但是，如果链接是 JavaScript onclick，则脚本将失败。
Here's my code:
这是我的代码：
<script type="text/javascript">
pageObj = {
init: function(){
$("body").fadeTo("slow", 1);
},
redirectPage: function(redirect){
window.location = redirect;
},
linkLoad: function(location){
$("body").fadeOut(1000, this.redirectPage(location));
}
};
$(document).ready(function() {
pageObj.init();
$("a").click(function(e){
e.preventDefault();
if (this.attr('onclick') !== undefined) {
eval(this.attr('onclick').val());
} else {
var location = this.href;
pageObj.linkLoad(location);
}
});
});
</script>
As you can see, I'm trying to do a check to see if the link has the onclickattribute, and then call the onclickfunction if it exists. How can I achieve this?
如您所见，我正在尝试检查链接是否具有onclick属性，然后调用onclick函数（如果存在）。我怎样才能做到这一点？
采纳答案by eyelidlessness
While Diodeus is correct that you need to wrap thisin a jQuery collection before using attr()(it's a method of a jQuery collection, not of an HTMLElement), you can just as well skip attr().
虽然 Diodeus 是正确的，您需要this在使用之前包装在 jQuery 集合中attr()（它是 jQuery 集合的方法，而不是HTMLElement），但您也可以跳过attr()。
$("a").click(function(e){
var location;
e.preventDefault();
if ($.isFunction(this.onclick)) {
this.onclick.call(this, e);
} else {
location = this.href;
pageObj.linkLoad(location);
}
});
Note that I used the property (when an HTML document loads, attributes are usually preloaded into properties, with on_______attributes being preloaded as methods. Also note that I used this.onclick.call()rather than eval(), setting the correct thisfor onclickmethods, and ensuring access to the event object as an argument.
请注意，我使用了属性（当加载 HTML 文档时，属性通常被预加载到属性中，on_______属性被预加载为方法。另请注意，我使用了this.onclick.call()而不是eval()，设置了正确this的onclick方法，并确保对事件对象的访问作为争论。
回答by Diodeus - James MacFarlane
Use: $(this).attrinstead of this.attr
用途：$(this).attr代替this.attr
This forces it into the context of jQuery.
这迫使它进入 jQuery 的上下文。
