jquery - 带有滚动条的下拉菜单在 iPad 上不起作用

Question

在我的导航栏中，我有一个可滚动的下拉列表。一旦用户悬停在它上面，它就会出现，他可以悬停上下滚动以选择一个链接。它在所有桌面浏览器中都能完美运行，但在 iPad 上，一旦显示下拉菜单，它就会卡住，用户无法上下滚动。

这是我使用的 JS:

var 最大高度 = 400;$(函数(){

$(".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");

});  

});

我不知道我是否解释得当(英语不是我的第一语言)，但你可以在 https://jsfiddle.net/x7L4zgfk/1/ 上看到我的意思。

Answer 1

复制自 JavaScript - mousemove event not triggered on iPad/iPhone

Just use jquery.event.move. Move events provide an easy way to set up press-move-release interactions on mouse AND touch devices. So you don't have to worry which device your users have.

Source and examples: http://stephband.info/jquery.event.move/