Css 防止在 WebKitBlink 中为 MacOS 触控板用户隐藏滚动条

发布于10月22日

WebKit/Blink's (Safari/Chrome) default behaviour on MacOS since 10.7 (Mac OS X Lion) is to hide scroll bars from trackpad users when they're not in use. This can be confusing; the scroll bar is often the only visual cue that an element is scrollable.

Example (jsfiddle)

HTML

<div class="frame">
    Foo<br />
    Bar<br />
    Baz<br />
    Help I'm trapped in an HTML factory! 
</div>

CSS

.frame {
    overflow-y: auto;
    border: 1px solid black;
    height: 3em;
    width: 10em;
    line-height: 1em;
}

WebKit (Chrome) Screenshot

Presto (Opera) Screenshot

screenshot of a div with a visible scroll bar

如何强制滚动条始终显示在WebKit中的可滚动元素上？

推荐答案

滚动条的外观可以用WebKit的-webkit-scrollbar个伪元素^[blog]控制.您可以通过将-webkit-appearance^[docs]设置为none来禁用默认外观和行为.

因为您要删除默认样式，所以您还需要自己指定样式，否则滚动条将永远不会显示.以下CSS重新创建隐藏滚动条的外观:

Example (jsfiddle)

CSS

.frame::-webkit-scrollbar {
    -webkit-appearance: none;
}

.frame::-webkit-scrollbar:vertical {
    width: 11px;
}

.frame::-webkit-scrollbar:horizontal {
    height: 11px;
}

.frame::-webkit-scrollbar-thumb {
    border-radius: 8px;
    border: 2px solid white; /* should match background, can't be transparent */
    background-color: rgba(0, 0, 0, .5);
}

.frame::-webkit-scrollbar-track { 
    background-color: #fff; 
    border-radius: 8px; 
}

WebKit (Chrome) Screenshot

screenshot showing webkit's scrollbar, without needing to hover