Mousewheel events are used in typical applications where the Mousewheel is used to control the size of an image or text. In most browsers (IE6, IE7, IE8, Opera 10+, Safari 5+), the mousewheel event is provided. The compatibility differences of the wheel event are somewhat eclectic. It is not ie8-pie and other pie, but FireFox pie and other pie. Unfortunately, FireFox 3.5+ does not support this event.

//IsFirefox is pseudo-code that you can implement yourself
mousewheel = isFirefox ? "DOMMouseScroll" : "mousewheel";

 " mousewheel "   In the event   " event.wheelDelta "   Property value: the value returned, if positive value means that the roller is scrolling up, if negative value means that the roller is scrolling down; The values returned are all 120  A multiple of, that is, the magnitude of the amplitude  =  The value returned  / 120 .
 " DOMMouseScroll "   In the event   " event.detail "   Property value: the value returned, if negative, indicates that the wheel is scrolling up (with   " event.wheelDelta "   If it is positive, it means the wheel is rolling down. The values returned are all  3  A multiple of, that is, the magnitude of the amplitude  =  The value returned  / 3 .
 " mousewheel "   In the event  Opera 10+  Is a special case, existing   " event.wheelDelta "   Properties, too   " event.detail "   Properties.