当文本为空时，CSS 背景图像大小不起作用

Question

下面是我要显示的背景图片的 CSS。它用于我页面上的可拖动元素以显示 Drag handle供用户拖动元素。

我的问题是 background-size: 16px 16px;也不width: 16px; heith: 16px;工作。

如果我的 <span> 中没有文本，它不会在页面上显示任何内容。我需要弄清楚如何让一个空的 span 标签具有我为此背景图片设置的宽度来显示？

http://codepen.io/jasondavis/pen/Hnyjf

HTML...

<div class="tools">

  <span class="handle"></span>

  <a href="#" class="collapse">-</a>

</div>

CSS...

.handle {
  cursor: move;
  position: relative;
  top: -4px;
  padding-top: 10px;
  width: 16px;
  height: 16px;
  background-size: 16px 16px;
  background-image:  
  url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA4AAAAOCAYAAAAfSC3RAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAyJpVFh0WE1MOmNvbS5hZG9iZS54bXAAAAAAADw/eHBhY2tldCBiZWdpbj0i77u/IiBpZD0iVzVNME1wQ2VoaUh6cmVTek5UY3prYzlkIj8+IDx4OnhtcG1ldGEgeG1sbnM6eD0iYWRvYmU6bnM6bWV0YS8iIHg6eG1wdGs9IkFkb2JlIFhNUCBDb3JlIDUuMC1jMDYxIDY0LjE0MDk0OSwgMjAxMC8xMi8wNy0xMDo1NzowMSAgICAgICAgIj4gPHJkZjpSREYgeG1sbnM6cmRmPSJodHRwOi8vd3d3LnczLm9yZy8xOTk5LzAyLzIyLXJkZi1zeW50YXgtbnMjIj4gPHJkZjpEZXNjcmlwdGlvbiByZGY6YWJvdXQ9IiIgeG1sbnM6eG1wPSJodHRwOi8vbnMuYWRvYmUuY29tL3hhcC8xLjAvIiB4bWxuczp4bXBNTT0iaHR0cDovL25zLmFkb2JlLmNvbS94YXAvMS4wL21tLyIgeG1sbnM6c3RSZWY9Imh0dHA6Ly9ucy5hZG9iZS5jb20veGFwLzEuMC9zVHlwZS9SZXNvdXJjZVJlZiMiIHhtcDpDcmVhdG9yVG9vbD0iQWRvYmUgUGhvdG9zaG9wIENTNS4xIFdpbmRvd3MiIHhtcE1NOkluc3RhbmNlSUQ9InhtcC5paWQ6MzM3NDRFNERCMTFBMTFFMkE2QUJFMTNBNTEzQzEzMUUiIHhtcE1NOkRvY3VtZW50SUQ9InhtcC5kaWQ6MzM3NDRFNEVCMTFBMTFFMkE2QUJFMTNBNTEzQzEzMUUiPiA8eG1wTU06RGVyaXZlZEZyb20gc3RSZWY6aW5zdGFuY2VJRD0ieG1wLmlpZDozMzc0NEU0QkIxMUExMUUyQTZBQkUxM0E1MTNDMTMxRSIgc3RSZWY6ZG9jdW1lbnRJRD0ieG1wLmRpZDozMzc0NEU0Q0IxMUExMUUyQTZBQkUxM0E1MTNDMTMxRSIvPiA8L3JkZjpEZXNjcmlwdGlvbj4gPC9yZGY6UkRGPiA8L3g6eG1wbWV0YT4gPD94cGFja2V0IGVuZD0iciI/PoCwBg8AAAAsSURBVHjaYqyurv7PAAGMUJooPhMDmYAFySQGNJPx8imycdSPo34kHQAEGACMAxGhnEmydQAAAABJRU5ErkJggg==);
}

Answer 1

因为空内联元素没有任何宽度。您可以将元素设置为内联 block 元素:

.handle {
  display: inline-block;
}