事件监听（addEventListener()）及其移除（removeEventListener）

html

<div id="box"></div>

js

<script type="text/javascript">
    var box = document.getElementById("box");
    function clickfn(){
        console.log("传到box上了");
    }
    function clickhandle(){
        console.log("aa");
    }


    function addEvent( obj,type,fn,capture ){
        if( obj.addEventListener ){
            obj.addEventListener( type,fn,false );
        }else if( obj.attachEvent ){
            obj.attachEvent('on',type,fn );
        }else{
            obj[ 'on'+type ] = fn;
        }
    }
    //移除监听函数
    function removeEventHandle(target,type,fn,capture){
        if(target.addEventListener){ //如果为true的话，进入
            target.removeEventListener(type,fn,capture);
        }else if( target.attachEvent ){
            //IE8以下版本
            target.detachEvent('on'+ type,fn,capture);
        }
    }
    addEvent(box,'click',clickfn,false);
    addEvent(box,'mouseover',clickhandle,false);
    removeEventHandle(box,'mouseover',clickhandle,false);
</script>