悬停菜单后，Bootstrap旋转木马刹车

Question

我有一个奇怪的行为，使用Bootstrap旋转木马在一个页面中的某个菜单效果。 基本上，如果我将鼠标悬停在菜单，引导旋转木马刹车，给我下面的错误：

铬：

Cannot read property 'offsetWidth' of undefined 

火狐：

$next[0] is undefined 

这是更新 JS的代码我正在使用的效果：

var marker = $('#marker'), 
    current = $('.current'); 

// Initialize the marker position and the active class 
current.addClass('active'); 
marker.css({ 
    // Place the marker in the middle of the border 
    bottom: -(marker.height()/2), 
    left: current.position().left, 
    width: current.outerWidth(), 
    display: "block" 
}); 


if (Modernizr.csstransitions) { 
    console.log("using css3 transitions"); 
$('li.list').mouseover(function() { 
    var self = $(this), 
     offsetLeft = self.position().left, 
     // Use the element under the pointer OR the current page item 
     width = self.outerWidth() || current.outerWidth(), 
     // Ternary operator, because if using OR when offsetLeft is 0, it is considered a falsy value, thus causing a bug for the first element. 
     left = offsetLeft == 0 ? 0 : offsetLeft || current.position().left; 
    // Play with the active class 
    $('.active').removeClass('active'); 
    self.addClass('active'); 
    marker.css({ 
     left: left, 
     width: width, 
    }); 
}); 

// When the mouse leaves the menu 
$('ul.UlList').mouseleave(function() { 
    // remove all active classes, add active class to the current page item 
    $('.active').removeClass('active'); 
    current.addClass('active'); 
    // reset the marker to the current page item position and width 
    marker.css({ 
     left: current.position().left, 
     width: current.outerWidth() 
    }); 
}); 

} else { 
console.log("using jquery animate"); 

$('li.list').mouseover(function() { 
    var self = $(this), 
     offsetLeft = self.position().left, 
     // Use the element under the pointer OR the current page item 
     width = self.outerWidth() || current.outerWidth(), 
     // Ternary operator, because if using OR when offsetLeft is 0, it is considered a falsy value, thus causing a bug for the first element. 
     left = offsetLeft == 0 ? 0 : offsetLeft || current.position().left; 
    // Play with the active class 
    $('.active').removeClass('active'); 
    self.addClass('active'); 
    marker.stop().animate({ 
     left: left, 
     width: width, 
    }, 300); 
}); 

// When the mouse leaves the menu 
$('ul.UlList').mouseleave(function() { 
    // remove all active classes, add active class to the current page item 
    $('.active').removeClass('active'); 
    current.addClass('active'); 
    // reset the marker to the current page item position and width 
    marker.stop().animate({ 
     left: current.position().left, 
     width: current.outerWidth() 
    }, 300); 
}); 
}; 

这里是再现这一问题的codepen： http://codepen.io/florinsimion/pen/AXaaOK

Answer 1

这是发生，因为$('li')将匹配所有网页上的li标签，包括旋转木马的。你需要选择你的菜单中li标签：

$('ul > li').mouseover(....) 
//^ add UL as parent for all your events 

一个更好的解决办法是使用特定类的菜单：

current = $('.my-menu .current'); 
$('.my-menu li').mouseover(....); 
$('ul.my-menu').mouseleave(....); 
$('.my-menu .active').removeClass('active'); 

不要忘记你的CSS，请拿看看这个演示：http://codepen.io/anon/pen/AXaaap