HTML

<div id="dash">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin nisi ligula, dapibus a volutpat sit amet, mattis et dui. Nunc porttitor accumsan orci id luctus. Phasellus ipsum metus, tincidunt non rhoncus id, dictum a lectus. Nam sed ipsum a urna ac
quam.</p>
</div>

jQuery

var p = $('#dash p');
var ks = $('#dash').height();
while ($(p).outerHeight() > ks) {
  $(p).text(function(index, text) {
    return text.replace(/\W*\s(\S)*$/, '...');
  });
}

CSS

#dash {
  width: 400px;
  height: 60px;
  overflow: hidden;
}

#dash p {
  padding: 10px;
  margin: 0;
}

结果

Lorem ipsum dolor sit amet， consectetur adipiscing elit.Proin nisi Ligula， dapibus a volutpat sit amet， mattis et...

杰斯菲德尔

75个字符

我已经尝试了最大宽度，但这打乱了我的布局。

使用max-width: 75ch，然后创建一个布局，当你超过这个宽度时不会乱。

这篇文章是关于一个CSS解决方案的，但这篇文章已经很老了，所以为了防止其他人偶然发现这一点，并且正在使用一个现代的JS框架，比如Angular 4+，有一个简单的方法可以通过Angular Pipes来实现这一点，而不必在CSS上瞎忙活。

可能也有“React”或“Vue”的方法来做到这一点。这只是为了展示如何在框架中完成它。

truncate-text.pipe.ts

/**
 * Helper to truncate text using JS in view only.
 *
 * This is pretty difficult to do reliably with CSS, especially when there are
 * multiple lines.
 *
 * Example: {{ value | truncateText:maxLength }} or {{ value | truncateText:45 }}
 *
 * If maxLength is not provided, the value will be returned without any truncating. If the
 * text is shorter than the maxLength, the text will be returned untouched. If the text is greater
 * than the maxLength, the text will be returned with 3 characters less than the max length plus
 * some ellipsis at the end to indicate truncation.
 *
 * For example: some really long text I won't bother writing it all ha...
 */
@Pipe({ name: 'truncateText' })
export class TruncateTextPipe implements PipeTransform {
  transform(value: string, ...args: any[]): any {
    const maxLength = args[0]
    const maxLengthNotProvided = !maxLength
    const isShorterThanMaximumLength = value.length < maxLength
    if (maxLengthNotProvided || isShorterThanMaximumLength) {
      return value
    }
    const shortenedString = value.substr(0, maxLength - 3)
    return `${shortenedString}...`
  }
}

app.component.html

<h1>{{ application.name | truncateText:45 }}</h1>

在所有浏览器中完全支持。

这在CSS中是不可能的，你必须使用Javascript。虽然你可以设置p的宽度为30个字符，下一个字母会自动下来，但这不会那么准确，如果字符是大写的，会有所不同。

HTML

<div id="dash">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin nisi ligula, dapibus a volutpat sit amet, mattis et dui. Nunc porttitor accumsan orci id luctus. Phasellus ipsum metus, tincidunt non rhoncus id, dictum a lectus. Nam sed ipsum a urna ac
quam.</p>
</div>

jQuery

var p = $('#dash p');
var ks = $('#dash').height();
while ($(p).outerHeight() > ks) {
  $(p).text(function(index, text) {
    return text.replace(/\W*\s(\S)*$/, '...');
  });
}

CSS

#dash {
  width: 400px;
  height: 60px;
  overflow: hidden;
}

#dash p {
  padding: 10px;
  margin: 0;
}

结果

Lorem ipsum dolor sit amet， consectetur adipiscing elit.Proin nisi Ligula， dapibus a volutpat sit amet， mattis et...

杰斯菲德尔