I have a <div> on my page with a fixed height, and overflow-y: scroll; set so that the content will scroll when it passes the bottom edge of the <div>. Nothing out of the ordinary.
For some bizarre reason, the mouse wheel will only scroll the content if the cursor is over empty space in the <div> or if it's over the scrollbar itself. If the cursor happens to be over any of the text content in the <div>, the mouse wheel won't do anything.
This happens in both Firefox and Chrome, so it isn't just a quirk of a particular rendering engine or something.
The <div> in question is overlaid on top of another via position: absolute;, so I'm assuming that somehow the <div> behind it is interfering with the mouse wheel event - but then you'd think the problem would be reversed (the <div> would scroll when the cursor was over the text, not over the empty space).
Anyone else ever see anything like this before? I'm stumped!
Got it - it's because I was using the FancyBox mousewheel plugin. This causes FancyBox to capture all mousewheel events (for use with scrolling through galleries). Since I'm not actually using any galleries, I have no need for it, so I took it out and immediately that fixed my problem.
来源：https://stackoverflow.com/questions/10449802/html-content-only-scrolls-with-scrollbar-not-mouse-wheel