JS wheel event onmousewheel usage introduction_javascript skills

In a typical application, the mouse wheel scrolls to control the size of pictures or text. For example, the Mousewheel event is used in interactive effects such as rotating the mouse wheel to achieve zooming. In most browsers (IE6, IE7, IE8, Opera 10, Safari 5), the "mousewheel" event is provided. The compatibility difference of the scroll wheel event is somewhat eclectic. It is not the IE8-party and other parties in the past, but the FireFox party and other parties. Firefox 3.5 does not support this event, but fortunately Firefox 3.5 provides another one. Equivalent event: "DOMMouseScroll", the compatible code is as follows:

Copy the code The code is as follows:

// isFirefox is pseudo code, you can implement it yourself
mousewheel = isFirefox ? "DOMMouseScroll" : "mousewheel";

"event.wheelDelta" attribute value in the "mousewheel" event: the returned value, If it is a positive value, it means the scroll wheel is scrolling upward; if it is a negative value, it means the scroll wheel is scrolling down; the returned values ​​are all multiples of 120, that is: amplitude = returned value / 120.
"event.detail" attribute value in the "DOMMouseScroll" event: the returned value. If it is a negative value, it means the wheel is scrolling upward (just the opposite of "event.wheelDelta"). If it is a positive value, it means the wheel is rolling down. Scroll; the returned values ​​are all multiples of 3, that is: amplitude = returned value/3.
The "mousewheel" event is a special case in Opera 10. It has both the "event.wheelDelta" attribute and the "event.detail" attribute.