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}`;
}
}

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

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}`;
}
}

根据单词限制长度

如果您想根据单词而不是字符进行截断，同时还允许一个选项查看完整的文本，可以试试这个方法。

来到这里寻找一个阅读更多的解决方案基于文字，分享自定义管道我最终写。

管:

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

@Pipe({
  name: 'readMore'
})
export class ReadMorePipe implements PipeTransform {

  transform(text: any, length: number = 20, showAll: boolean = false, suffix: string = '...'): any {
    
    if (showAll) {
      return text;
    }

    if ( text.split(" ").length > length ) {
      
      return text.split(" ").splice(0, length).join(" ") + suffix;
    }

    return text;
  }

}

在模板:

<p [innerHTML]="description | readMore:30:showAll"></p>
<button (click)="triggerReadMore()" *ngIf="!showAll">Read More<button>

组件:

export class ExamplePage implements OnInit {

    public showAll: any = false;
    
    triggerReadMore() {
        this.showAll = true;
    }
    
}

在模块:

import { ReadMorePipe } from '../_helpers/read-more.pipe';

@NgModule({
  declarations: [ReadMorePipe]
})
export class ExamplePageModule {}

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}}

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…"