import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'truncate',
})
export class TruncatePipe implements PipeTransform {
  transform(value: string, limit: number, trail = '...'): string {
    if (value.length <= limit) {
      return value;
    }

    return value.substring(0, limit - trail.length).replace(/\s+$/, '') + trail;
  }
}

{{ str | truncate: 20 }}
{{ str | truncate: 20:'>>>'] }}

如果需要用单词截断:

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'truncateByWords',
})
export class TruncateByWordsPipe implements PipeTransform {
  transform(value: string, limit: number, trail = '...'): string {
    if (value.length <= limit) {
      return value;
    }

    const substr = value.substring(0, limit - trail.length).split(' ');
    const isLastWordFull = value
      .split(' ')
      .find(w => w === substr[substr.length - 1]);

    if (isLastWordFull) {
      return substr.join(' ') + trail;
    }

    return substr.slice(0, -1).join(' ') + trail;
  }
}

{{ str | truncateByWords: 20 }}
{{ str | truncateByWords: 20:'>>>'] }}

如果你想要截断一些单词并添加一个省略号，你可以使用这个函数:

truncate(value: string, limit: number = 40, trail: String = '…'): string {
  let result = value || '';

  if (value) {
    const words = value.split(/\s+/);
    if (words.length > Math.abs(limit)) {
      if (limit < 0) {
        limit *= -1;
        result = trail + words.slice(words.length - limit, words.length).join(' ');
      } else {
        result = words.slice(0, limit).join(' ') + trail;
      }
    }
  }

  return result;
}

例子:

truncate('Bacon ipsum dolor amet sirloin tri-tip swine', 5, '…')
> "Bacon ipsum dolor amet sirloin…"

来自: https://github.com/yellowspot/ng2-truncate/blob/master/src/truncate-words.pipe.ts

如果你想要截断一些字母，但不删减单词，请使用以下命令:

truncate(value: string, limit = 25, completeWords = true, ellipsis = '…') {
  let lastindex = limit;
  if (completeWords) {
    lastindex = value.substr(0, limit).lastIndexOf(' ');
  }
  return `${value.substr(0, limit)}${ellipsis}`;
}

例子:

truncate('Bacon ipsum dolor amet sirloin tri-tip swine', 19, true, '…')
> "Bacon ipsum dolor…"

truncate('Bacon ipsum dolor amet sirloin tri-tip swine', 19, false, '…')
> "Bacon ipsum dolor a…"

我一直在使用这个模块ng2 truncate，它很简单，导入模块和u已经准备好了…在{{data。标题| truncate: 20}}

您可以根据CSS截断文本。它有助于根据宽度截断文本，而不是固定字符。

例子

CSS

.truncate {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.content {
    width:100%;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

HTML

<div class="content">
    <span class="truncate">Lorem Ipsum is simply dummied text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</span>
</div>

注意:这段代码一行使用full，而不是多行。

如果你想用Angular来做，那么Ketan的解决方案是最好的

用可选参数截断管道:

Limit - string最大长度 completeWords -标记在最近的完整单词处截断，而不是字符 省略号——附加在后面的后缀

-

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'truncate'
})
export class TruncatePipe implements PipeTransform {
  transform(value: string, limit = 25, completeWords = false, ellipsis = '...') {
    if (completeWords) {
      limit = value.substr(0, limit).lastIndexOf(' ');
    }
    return value.length > limit ? value.substr(0, limit) + ellipsis : value;
  }
}

不要忘记添加一个模块条目。

@NgModule({
  declarations: [
    TruncatePipe
  ]
})
export class AppModule {}

使用

示例字符串:

public longStr = 'A really long string that needs to be truncated';

标记:

  <h1>{{longStr | truncate }}</h1> 
  <!-- Outputs: A really long string that... -->

  <h1>{{longStr | truncate : 12 }}</h1> 
  <!-- Outputs: A really lon... -->

  <h1>{{longStr | truncate : 12 : true }}</h1> 
  <!-- Outputs: A really... -->

  <h1>{{longStr | truncate : 12 : false : '***' }}</h1> 
  <!-- Outputs: A really lon*** -->

刚刚尝试了@蒂莫西佩雷斯的回答，并添加了一行

if (value.length < limit)
   return `${value.substr(0, limit)}`;

to

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'truncate'
})
export class TruncatePipe implements PipeTransform {
transform(value: string, limit = 25, completeWords = false, ellipsis = '...') {

   if (value.length < limit)
   return `${value.substr(0, limit)}`;

   if (completeWords) {
     limit = value.substr(0, limit).lastIndexOf(' ');
   }
   return `${value.substr(0, limit)}${ellipsis}`;
}
}