js导航下拉菜单

使用定时器、鼠标移动事件

var img = $('#user_head');
        var menu = $('.nav_list');
        var i=0;
        var timer;
        img.mouseenter(function () {
            clearTimeout(timer)
            menu.show()
        })
        img.mouseleave(function () {
            timer = window.setTimeout(function () {
                menu.hide()
            },500)
        })
        menu.mouseenter(function () {
            clearTimeout(timer)
            // menu.css('visibility','vidible')
        })
        menu.mouseleave(function () {
            menu.hide()
        })