因为我不能评论，所以我将写这作为一个答案!

请理解css选择器“:hover”和hover事件之间的区别!

":hover"是一个css选择器，当像这样使用$("#elementId").is(":hover")时，它确实与事件一起被删除了，但它的意思是它真的与jQuery事件无关。

如果你输入$("#elementId:hover")，元素只会在你用鼠标悬停时被选中。上面的语句将适用于所有jQuery版本，因为你选择这个元素与纯合法的css选择。

另一方面，事件悬停

$("#elementId").hover(
     function() { 
         doSomething(); 
     }
); 

在jQuery 1.8的时候已经被弃用了。

When the event name "hover" is used, the event subsystem converts it to "mouseenter mouseleave" in the event string. This is annoying for several reasons: Semantics: Hovering is not the same as the mouse entering and leaving an element, it implies some amount of deceleration or delay before firing. Event name: The event.type returned by the attached handler is not hover, but either mouseenter or mouseleave. No other event does this. Co-opting the "hover" name: It is not possible to attach an event with the name "hover" and fire it using .trigger("hover"). The docs already call this name "strongly discouraged for new code", I'd like to deprecate it officially for 1.8 and eventually remove it.

为什么他们删除用法是(":hover")不清楚，但哦，好吧，你仍然可以像上面那样使用它，这里有一个小技巧，仍然使用它。

(function ($) {
   /** 
    * :hover selector was removed from jQuery 1.8+ and cannot be used with .is(":hover") 
    * but using it in this way it works as :hover is css selector! 
    *
    **/
    $.fn.isMouseOver = function() {
        return $(this).parent().find($(this).selector + ":hover").length > 0;
    };
})(jQuery);

哦，我不建议使用超时版本，因为这带来了很多复杂性，如果没有其他方法，请使用超时功能，相信我，在95%的情况下有另一种方法!

希望我能帮到一些人。

Greetz安迪

这里有一个技术，它不依赖于jquery，并使用本机DOM匹配API。它使用厂商前缀支持回到IE9的浏览器。详情请参阅caniuse.com上的matchesselector。

首先创建matchesSelector函数，如下所示:

var matchesSelector = (function(ElementPrototype) {
var fn = ElementPrototype.matches ||
          ElementPrototype.webkitMatchesSelector ||
          ElementPrototype.mozMatchesSelector ||
          ElementPrototype.msMatchesSelector;

return function(element, selector) {
  return fn.call(element, selector);
};

})(Element.prototype);

然后，检测悬停:

var mouseIsOver = matchesSelector(element, ':hover');

You can test with jQuery if any child div has a certain class. Then by applying that class when you mouse over and out out a certain div, you can test whether your mouse is over it, even when you mouse over a different element on the page Much less code this way. I used this because I had spaces between divs in a pop-up, and I only wanted to close the pop up when I moved off of the pop up, not when I was moving my mouse over the spaces in the pop up. So I called a mouseover function on the content div (which the pop up was over), but it would only trigger the close function when I moused-over the content div, AND was outside the pop up!

$(".pop-up").mouseover(function(e)
    {
    $(this).addClass("over");
    });

$(".pop-up").mouseout(function(e)
    {
    $(this).removeClass("over");
    });


$("#mainContent").mouseover(function(e){
            if (!$(".expanded").hasClass("over")) {
            Drupal.dhtmlMenu.toggleMenu($(".expanded"));
        }
    });

因为我不能评论，所以我将写这作为一个答案!

请理解css选择器“:hover”和hover事件之间的区别!

":hover"是一个css选择器，当像这样使用$("#elementId").is(":hover")时，它确实与事件一起被删除了，但它的意思是它真的与jQuery事件无关。

如果你输入$("#elementId:hover")，元素只会在你用鼠标悬停时被选中。上面的语句将适用于所有jQuery版本，因为你选择这个元素与纯合法的css选择。

另一方面，事件悬停

$("#elementId").hover(
     function() { 
         doSomething(); 
     }
); 

在jQuery 1.8的时候已经被弃用了。

When the event name "hover" is used, the event subsystem converts it to "mouseenter mouseleave" in the event string. This is annoying for several reasons: Semantics: Hovering is not the same as the mouse entering and leaving an element, it implies some amount of deceleration or delay before firing. Event name: The event.type returned by the attached handler is not hover, but either mouseenter or mouseleave. No other event does this. Co-opting the "hover" name: It is not possible to attach an event with the name "hover" and fire it using .trigger("hover"). The docs already call this name "strongly discouraged for new code", I'd like to deprecate it officially for 1.8 and eventually remove it.

为什么他们删除用法是(":hover")不清楚，但哦，好吧，你仍然可以像上面那样使用它，这里有一个小技巧，仍然使用它。

(function ($) {
   /** 
    * :hover selector was removed from jQuery 1.8+ and cannot be used with .is(":hover") 
    * but using it in this way it works as :hover is css selector! 
    *
    **/
    $.fn.isMouseOver = function() {
        return $(this).parent().find($(this).selector + ":hover").length > 0;
    };
})(jQuery);

哦，我不建议使用超时版本，因为这带来了很多复杂性，如果没有其他方法，请使用超时功能，相信我，在95%的情况下有另一种方法!

希望我能帮到一些人。

Greetz安迪

使用 evt.originalEvent.composedPath（）

MouseEvent给出了鼠标最近与之交互的HTMLElement的数组。最后一个元素是最外层的(也就是说，它总是Window)。

MouseEvent composedPath()示例如下:

通过检查该数组中是否存在可点击的元素，您将知道是否在特定元素上有鼠标悬停…

$(window).on("mouseup", onMouseUp);
const $someButton = $("a.yourButton");

function onMouseUp(evt) {
  const path = evt.originalEvent.composedPath();
  if(path.indexOf($someButton[0]) !== -1){
    // released mouse over button
  }else{
    // did not release mouse over button
  }
}

扩展什么'Happytime harry'说，一定要使用.data() jquery函数来存储超时id。这样，当'mouseenter'在同一个元素上被触发时，你可以很容易地检索超时id，允许你消除触发，让你的工具提示消失。