修改版本的jockeisorby的回答，修复事件处理程序没有被正确删除。

copyToClipboard(item): void {
    let listener = (e: ClipboardEvent) => {
        e.clipboardData.setData('text/plain', (item));
        e.preventDefault();
    };

    document.addEventListener('copy', listener);
    document.execCommand('copy');
    document.removeEventListener('copy', listener);
}

用纯Angular和ViewChild为自己找到了最简单的解决方案。

import { Component, ViewChild } from '@angular/core';

@Component({
  selector: 'cbtest',
  template: `
    <input type="text" #inp/>
    <input type="button" (click)="copy ()" value="copy now"/>`
})

export class CbTestComponent
{
  @ViewChild ("inp") inp : any;

  copy ()
  {
    // this.inp.nativeElement.value = "blabla";  // you can set a value manually too

    this.inp.nativeElement.select ();   // select
    document.execCommand ("copy");      // copy
    this.inp.nativeElement.blur ();     // unselect
  }
}

我认为在复制文本时，这是一个更干净的解决方案:

copyToClipboard(item) {
    document.addEventListener('copy', (e: ClipboardEvent) => {
      e.clipboardData.setData('text/plain', (item));
      e.preventDefault();
      document.removeEventListener('copy', null);
    });
    document.execCommand('copy');
  }

然后在html中的click事件上调用copyToClipboard。(点击)= " copyToClipboard (texttocopy)”。

以下方法可用于复制消息:-

export function copyTextAreaToClipBoard(message: string) {
  const cleanText = message.replace(/<\/?[^>]+(>|$)/g, '');
  const x = document.createElement('TEXTAREA') as HTMLTextAreaElement;
  x.value = cleanText;
  document.body.appendChild(x);
  x.select();
  document.execCommand('copy');
  document.body.removeChild(x);
}

使用angular cdk复制，

Module.ts

import {ClipboardModule} from '@angular/cdk/clipboard';

以编程方式复制一个字符串:

class MyComponent {
  constructor(private clipboard: Clipboard) {}

  copyHeroName() {
    this.clipboard.copy('Alphonso');
  }
}

点击一个元素通过HTML复制:

<button [cdkCopyToClipboard]="longText" [cdkCopyToClipboardAttempts]="2">Copy text</button>

参考: https://material.angular.io/cdk/clipboard/overview

// for copy the text
import { Clipboard } from "@angular/cdk/clipboard"; // first import this in .ts
 constructor(
    public clipboard: Clipboard
  ) { }   
 <button class="btn btn-success btn-block"(click) = "onCopy('some text')" > Copy< /button>

 onCopy(value) {
     this.clipboard.copy(value);
    }


 // for paste the copied text on button click :here is code
    
    <button class="btn btn-success btn-block"(click) = "onpaste()" > Paste < /button>
    
    onpaste() {
      navigator['clipboard'].readText().then(clipText => {
        console.log(clipText);
      });
    }