您可以使用 Javascript 执行此操作。这是一个计算元素中可见字符数的函数,与应用于元素的外部 css 表和内联样式无关。我只在 Chrome 中测试过,但我认为它是跨浏览器友好的:
function count_visible(el){
var padding, em, numc;
var text = el.firstChild.data;
var max = el.clientWidth;
var tmp = document.createElement('span');
var node = document.createTextNode();
tmp.appendChild(node);
document.body.appendChild(tmp);
if(getComputedStyle)
tmp.style.cssText = getComputedStyle(el, null).cssText;
else if(el.currentStyle)
tmp.style.cssText = el.currentStyle.cssText;
tmp.style.position = 'absolute';
tmp.style.overflow = 'visible';
tmp.style.width = 'auto';
// Estimate number of characters that can fit.
padding = tmp.style.padding;
tmp.style.padding = '0';
tmp.innerHTML = 'M';
el.parentNode.appendChild(tmp);
em = tmp.clientWidth;
tmp.style.padding = padding;
numc = Math.floor(max/em);
var width = tmp.clientWidth;
// Only one of the following loops will iterate more than one time
// Depending on if we overestimated or underestimated.
// Add characters until we reach overflow width
while(width < max && numc <= text.length){
node.nodeValue = text.substring(0, ++numc);
width = tmp.clientWidth;
}
// Remove characters until we no longer have overflow
while(width > max && numc){
node.nodeValue = text.substring(0, --numc);
width = tmp.clientWidth;
}
// Remove temporary div
document.body.removeChild(tmp);
return numc;
}
JSFiddle 示例