监听 鼠标滚轮放大缩小 jq 原生
jq
// IE9, Chrome, Safari, Opera
$('xx').on("mousewheel",MouseWheelHandler);
// Firefox
$('xx').on("DOMMouseScroll",MouseWheelHandler);
// 鼠标滚轮放大缩小=
function MouseWheelHandler(event){
var type = event.type;
if (type == 'DOMMouseScroll' || type == 'mousewheel') {
event.delta = (event.originalEvent.wheelDelta) ? event.originalEvent.wheelDelta / 120 : -(event.detail || 0) / 3;
}
console.log(event.delta)
if(event.delta == 1){ //上滚
//业务代码
}else if(event.delta == -1){ //下滚 放大
//业务代码
}else{
console.log("鼠标滚轮放大缩小状态获取失败")
}
};
// 解绑
$(_this.el.imgViewer).off("mousewheel");
$(_this.el.imgViewer).off("DOMMouseScroll");
原生js
var myimage = document.getElementById("img");
if (myimage.addEventListener) {
//addEventListener适用于版本较新的IE浏览器 ,如IE9以及火狐浏览器,
myimage.addEventListener("mousewheel", MouseWheelHandler, false);
// Firefox浏览器使用的滚轮事件是 DOMMouseScroll
myimage.addEventListener("DOMMouseScroll", MouseWheelHandler, false);
}
//attachEvent适用于旧的 IE浏览器,IE 6/7/8
else myimage.attachEvent("onmousewheel", MouseWheelHandler);
//第三个参数设置为true就在捕获过程中执行处理函数,反之就在冒泡过程中执行处理函数。
function MouseWheelHandler(e) {
var e = window.event;
var delta = Math.max(-1, Math.min(1, (e.wheelDelta)));
myimage.style.width = Math.max(727, myimage.width + (30 * delta)) + "px";
myimage.style.height = Math.max(500, myimage.height + (30 * delta)) + "px";
return false;
}
detail与wheelDelta只各取两个值,detail只取±3,wheelDelta只取±120,其中对于wheelDelta正数表示为向上,负数表示向下,而对于detail则相反。