在下拉菜单选项上添加滚动条 [英] Add scrollbar on dropdown menu options

问题描述

我试图添加一个滚动条到下拉菜单选项，所以当用户点击菜单时，它不会显示所有的选项一直到结束。我尝试了

I am trying to add a scrollbar to a dropdown menu options so when user clicks the menu it won't show all the options all the way till end. I tried

<select name='menu'>
  <option value='1'>first item</option>
  <option value='2'>second item</option>
  <option value='3'>third item</option>
  <option value='4'>fourth item</option>
  <option value='5'>fifth item</option>
  <option>........
  <option>........
  //I have many options.....
</select>

我尝试这个CSS，但它只能在菜单本身，

I try this css but it only works on the menu itself, not options.

select {
height:50px;
overflow-y: scroll;
}

有任何想法吗？非常感谢。

Any thoughts? Thanks a lot.

推荐答案

这也是我很好的处理方式：）

This is also I nice way of handeling it :)

http://css-tricks.com/long-dropdowns-solution/

从以上链接：

var maxHeight = 400; $(function(){

$(".dropdown > li").hover(function() {

     var $container = $(this),
         $list = $container.find("ul"),
         $anchor = $container.find("a"),
         height = $list.height() * 1.1,       // make sure there is enough room at the bottom
         multiplier = height / maxHeight;     // needs to move faster if list is taller

    // need to save height here so it can revert on mouseout            
    $container.data("origHeight", $container.height());

    // so it can retain it's rollover color all the while the dropdown is open
    $anchor.addClass("hover");

    // make sure dropdown appears directly below parent list item    
    $list
        .show()
        .css({
            paddingTop: $container.data("origHeight")
        });

    // don't do any animation if list shorter than max
    if (multiplier > 1) {
        $container
            .css({
                height: maxHeight,
                overflow: "hidden"
            })
            .mousemove(function(e) {
                var offset = $container.offset();
                var relativeY = ((e.pageY - offset.top) * multiplier) - ($container.data("origHeight") * multiplier);
                if (relativeY > $container.data("origHeight")) {
                    $list.css("top", -relativeY + $container.data("origHeight"));
                };
            });
    }

}, function() {

    var $el = $(this);

    // put things back to normal
    $el
        .height($(this).data("origHeight"))
        .find("ul")
        .css({ top: 0 })
        .hide()
        .end()
        .find("a")
        .removeClass("hover");

});

// Add down arrow only to menu items with submenus
$(".dropdown > li:has('ul')").each(function() {
    $(this).find("a:first").append("<img src='images/down-arrow.png' />");
});

}）;

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