JavaScript mouseover/mouseout issue with child element

问题

I have this little problem and I am requesting for your help. I have a div element, inside which I have an img element, like this

<div id="parent" onmouseover="MyFuncHover()" onmouseout="MyFuncOut()">
    <img id="child" src="button.png" style="visibility: hidden" />
</div>

<script type="text/javascript">
    function MyFuncHover() {
        // Here I have some code that makes the "child" visible
    }

    function MyFuncOut() {
        // Here I have some code that makes the "child" invisible again
    }
</script>

As you, see, the image is a child of the div. I want that only when I leave the div, the child to disappear. Yet, it looks like when I move the mouse over the image, the MyFuncOut() function is called (because, I suppose, I leave the div by hovering the image). I don't want that to happen. I want the MyFuncOut() function to be called only when I leave the div area.

I didn't know that when you move your mouse over a child control, it's parent calls the mouseout event (even if I am over the child, I am still over the parent, too). I am trapped into this and I need a little of your good advice. Thanks!

CHANGES

O.K. Event bubbling will not send the "mouseout" event to the parent when I "mouseout" the child. It also won't send the "mouseover" event to the parent when I "mouseover" the child. That's not what I need. I need the "mouseout" event of the parent to not be sent when I "mouseover" the child. Get it? Event bubbling is useful when I don't want, for example, a click event on the child to be propagated to the parent, but this is not my case. What is weird is that I have other elements inside the same parent that don't fire the "mouseout" event of the parent when I "mouseover" them.

回答1:

you can use "mouseenter" and "mouseleave" events available in jquery, here is the below code,

$(document).ready(function () {
        $("#parent").mouseenter(function () {
            $("#child").show();
        });
        $("#parent").mouseleave(function () {
            $("#child").hide();
        });
    });

above is to attach an event,

<div id="parent">
    <img id="child" src="button.png" style="display:none;" />
</div>

回答2:

You can use the solution below, which it's pure javascript and I used with success.

var container = document.getElementById("container");
var mouse = {x: 0, y: 0};

function mouseTracking(e) {
    mouse.x = e.clientX || e.pageX;
    mouse.y = e.clientY || e.pageY;
    var containerRectangle = container.getBoundingClientRect();

    if (mouse.x > containerRectangle.left && mouse.x < containerRectangle.right &&
            mouse.y > containerRectangle.top && mouse.y < containerRectangle.bottom) {
        // Mouse is inside container.
    } else {
        // Mouse is outside container.
    }
}
document.onmousemove = function () {
    if (document.addEventListener) {
        document.addEventListener('mousemove', function (e) {
            mouseTracking(e);
        }, false);
    } else if (document.attachEvent) {
        // For IE8 and earlier versions.
        mouseTracking(window.event);
    }
}

I hope it helps.

回答3:

Just add an if statement to your MyFuncOut function which checks the target is not the image

if (event.target !== imageNode) {
     imageNode.style.display = 'none'
}

回答4:

I've had problems with this too and couldn't get it to work. This is what I did instead. It's much easier and isn't JavaScript so it's faster and can't be turned off.

div.container {
    opacity:0.0;
    filter:alpha(opacity="00");
}

div.container:hover {
    opacity:1.0;
    filter:alpha(opacity="100");
}

You can even add the CSS3 transition for opacity to give it a smoother feel to it.

回答5:

Simply set css of the child element pointer-event:none; See example:

#parent {
  width: 500px;
  height: 500px;
  border: 1px solid black;
}

#child {
  width: 200px;
  pointer-events: none; # this does the trick
}

<div id="parent" onmouseover="MyFuncHover()" onmouseout="MyFuncOut()">
    <img id="child" src="https://i2.wp.com/beebom.com/wp-content/uploads/2016/01/Reverse-Image-Search-Engines-Apps-And-Its-Uses-2016.jpg?w=640&ssl=1" />
</div>

<script type="text/javascript">
    function MyFuncHover() {
      console.log("mouse over")
    }

    function MyFuncOut() {
      console.log("mouse out")
    }
</script>

来源：https://stackoverflow.com/questions/10618001/javascript-mouseover-mouseout-issue-with-child-element