鼠标滚轮事件和Mac触控板双指事件用HTML5实现鼠标滚轮事件放大缩小图片的功能

 // creates a global "addWheelListener" method // example: addWheelListener( elem, function( e ) { console.log( e.deltaY ); e.preventDefault(); } ); (function(window,document) { var prefix = "", _addEventListener, onwheel, support; // detect event model if ( window.addEventListener ) { _addEventListener = "addEventListener"; } else { _addEventListener = "attachEvent"; prefix = "on"; } // detect available wheel event support = "onwheel" in document.createElement("div") ? "wheel" : // 各个厂商的高版本浏览器都支持"wheel" document.onmousewheel !== undefined ? "mousewheel" : // Webkit 和 IE一定支持"mousewheel" "DOMMouseScroll"; // 低版本firefox window.addWheelListener = function( elem, callback, useCapture ) { _addWheelListener( elem, support, callback, useCapture ); // handle MozMousePixelScroll in older Firefox if( support == "DOMMouseScroll" ) { _addWheelListener( elem, "MozMousePixelScroll", callback, useCapture ); } }; function _addWheelListener( elem, eventName, callback, useCapture ) { elem[ _addEventListener ]( prefix + eventName, support == "wheel" ? callback : function( originalEvent ) { !originalEvent && ( originalEvent = window.event ); // create a normalized event object var event = { // keep a ref to the original event object originalEvent: originalEvent, target: originalEvent.target || originalEvent.srcElement, type: "wheel", deltaMode: originalEvent.type == "MozMousePixelScroll" ? 0 : 1, deltaX: 0, deltaZ: 0, preventDefault: function() { originalEvent.preventDefault ? originalEvent.preventDefault() : originalEvent.returnValue = false; } }; // calculate deltaY (and deltaX) according to the event if ( support == "mousewheel" ) { event.deltaY = - 1/40 * originalEvent.wheelDelta; // Webkit also support wheelDeltaX originalEvent.wheelDeltaX && ( event.deltaX = - 1/40 * originalEvent.wheelDeltaX ); } else { event.deltaY = originalEvent.detail; } // it's time to fire the callback return callback( event ); }, useCapture || false ); } })(window,document); 

 function wheelEvent (e) { if (Math.abs(e.deltaX) !== 0 && Math.abs(e.deltaY) !== 0) return console.log('没有固定方向'); if (e.deltaX < 0) return console.log('向右'); if (e.deltaX > 0) return console.log('向左'); if (e.ctrlKey) { if (e.deltaY > 0) return console.log('向内'); if (e.deltaY < 0) return console.log('向外'); } else { if (e.deltaY > 0) return console.log('向上'); if (e.deltaY < 0) return console.log('向下'); } } 

 ctrlKey: originalEvent.ctrlKey || false,