我有一个跨度与动态数据在我的页面,与省略号风格。

.my-class
{
  text-overflow: ellipsis;
  overflow: hidden;
  white-space: nowrap;  
  width: 71px;
}
<span id="myId" class="my-class"></span>
document.getElementById('myId').innerText = "...";

我想在这个元素的工具提示中添加相同的内容,但我希望它只在内容较长且省略号出现在屏幕上时才会出现。 有什么办法可以做到吗? 当省略号被激活时,浏览器是否抛出一个事件?

*浏览器:Internet Explorer


当前回答

这就是我最终基于https://stackoverflow.com/a/13259660/1714951所做的,并在元素不再溢出时添加title属性的删除。这是纯JS (ES6),使用事件委托的性能(当使用几个元素与同一类)和保护子句的可读性:

// You may want to change document by an element closer to your target
// so that the handler is not executed as much
document.addEventListener( 'mouseenter', event => {
    let eventTarget = event.target;
    // This could be easily applied to text-truncate instead of my-class if you use bootstrap
    if ( !eventTarget.classList?.contains( 'my-class' ) ) {
        return;
    }
    if ( eventTarget.offsetWidth < eventTarget.scrollWidth ) {
        eventTarget.setAttribute( 'title', eventTarget.innerText );
        return;
    }
    eventTarget.removeAttribute( 'title' );
}, true );

其他回答

这就是我最终基于https://stackoverflow.com/a/13259660/1714951所做的,并在元素不再溢出时添加title属性的删除。这是纯JS (ES6),使用事件委托的性能(当使用几个元素与同一类)和保护子句的可读性:

// You may want to change document by an element closer to your target
// so that the handler is not executed as much
document.addEventListener( 'mouseenter', event => {
    let eventTarget = event.target;
    // This could be easily applied to text-truncate instead of my-class if you use bootstrap
    if ( !eventTarget.classList?.contains( 'my-class' ) ) {
        return;
    }
    if ( eventTarget.offsetWidth < eventTarget.scrollWidth ) {
        eventTarget.setAttribute( 'title', eventTarget.innerText );
        return;
    }
    eventTarget.removeAttribute( 'title' );
}, true );

我有CSS类,它决定在哪里放省略号。在此基础上,我做以下操作(元素集可能不同,我写那些,使用省略号,当然它可以是一个单独的类选择器):

$(document).on('mouseover', 'input, td, th', function() {
    if ($(this).css('text-overflow') && typeof $(this).attr('title') === 'undefined') {
        $(this).attr('title', $(this).val());
    }
});

下面是另外两个纯CSS解决方案:

在适当的位置显示截短的文本:

.overflow { overflow: hidden; -ms-text-overflow: ellipsis; text-overflow: ellipsis; white-space: nowrap; } .overflow:hover { overflow: visible; } .overflow:hover span { position: relative; background-color: white; box-shadow: 0 0 4px 0 black; border-radius: 1px; } <div> <span class="overflow" style="float: left; width: 50px"> <span>Long text that might overflow.</span> </span> Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ad recusandae perspiciatis accusantium quas aut explicabo ab. Doloremque quam eos, alias dolore, iusto pariatur earum, ullam, quidem dolores deleniti perspiciatis omnis. </div>

显示任意的“工具提示”:

.wrap { position: relative; } .overflow { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; pointer-events:none; } .overflow:after { content:""; display: block; position: absolute; top: 0; right: 0; width: 20px; height: 15px; z-index: 1; border: 1px solid red; /* for visualization only */ pointer-events:initial; } .overflow:hover:after{ cursor: pointer; } .tooltip { /* visibility: hidden; */ display: none; position: absolute; top: 10; left: 0; background-color: #fff; padding: 10px; -webkit-box-shadow: 0 0 50px 0 rgba(0,0,0,0.3); opacity: 0; transition: opacity 0.5s ease; } .overflow:hover + .tooltip { /*visibility: visible; */ display: initial; transition: opacity 0.5s ease; opacity: 1; } <div> <span class="wrap"> <span class="overflow" style="float: left; width: 50px">Long text that might overflow</span> <span class='tooltip'>Long text that might overflow.</span> </span> Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ad recusandae perspiciatis accusantium quas aut explicabo ab. Doloremque quam eos, alias dolore, iusto pariatur earum, ullam, quidem dolores deleniti perspiciatis omnis. </div>

我们需要检测是否真的应用了省略号,然后显示一个工具提示来显示全文。仅仅比较“这个”是不够的。offsetWidth < this。scrollWidth"当元素几乎包含了它的内容,但宽度只多了一到两个像素,特别是对于全宽的中文/日语/韩语字符的文本。

这里有一个例子:http://jsfiddle.net/28r5D/5/

我发现了一种改进省略号检测的方法:

“这相比较。offsetWidth < this。首先,如果失败,继续步骤#2。 暂时切换css样式为{'overflow': 'visible', 'white-space': 'normal', 'word-break': 'break-all'}。 让浏览器做中继布局。如果发生换行,元素将扩展其高度,这也意味着需要省略号。 恢复css样式。

以下是我的改进:http://jsfiddle.net/28r5D/6/

这就是我的解决办法,真是妙不可言!

    $(document).on('mouseover', 'input, span', function() {
      var needEllipsis = $(this).css('text-overflow') && (this.offsetWidth < this.scrollWidth);
      var hasNotTitleAttr = typeof $(this).attr('title') === 'undefined';
      if (needEllipsis === true) {
          if(hasNotTitleAttr === true){
            $(this).attr('title', $(this).val());
          }
      }
      if(needEllipsis === false && hasNotTitleAttr == false){
        $(this).removeAttr('title');
      }
  });