你的代码应该工作完美，我用同样的方式。只需要确保如果click事件是从弹出屏幕中触发的，比如bootstrap模式或其他，创建的元素必须在该模式中，否则它不会被复制。您总是可以给出该模式中元素的id(作为第二个参数)，并使用getElementById检索它，然后将新创建的元素附加到该元素而不是文档。就像这样:

copyToClipboard = (text, elementId) => {
  const textField = document.createElement('textarea');
  textField.innerText = text;
  const parentElement = document.getElementById(elementId);
  parentElement.appendChild(textField);
  textField.select();
  document.execCommand('copy');
  parentElement.removeChild(textField);
}

import React, { Component } from 'react';

export default class CopyTextOnClick extends Component {
    copyText = () => {
        this.refs.input.select();

        document.execCommand('copy');

        return false;
    }

    render () {
        const { text } = this.state;

        return (
            <button onClick={ this.copyText }>
                { text }

                <input
                    ref="input"
                    type="text"
                    defaultValue={ text }
                    style={{ position: 'fixed', top: '-1000px' }} />
            </button>
        )
    }
}

找到了最好的方法。我是说最快的方法:w3school

https://www.w3schools.com/howto/howto_js_copy_clipboard.asp

在react函数组件中。创建名为handleCopy的函数:

function handleCopy() {
  // get the input Element ID. Save the reference into copyText
  var copyText = document.getElementById("mail")
  // select() will select all data from this input field filled  
  copyText.select()
  copyText.setSelectionRange(0, 99999)
  // execCommand() works just fine except IE 8. as w3schools mention
  document.execCommand("copy")
  // alert the copied value from text input
  alert(`Email copied: ${copyText.value} `)
}

<>
              <input
                readOnly
                type="text"
                value="exemple@email.com"
                id="mail"
              />
              <button onClick={handleCopy}>Copy email</button>

</>

如果不使用React, w3schools也有一个很酷的方法来做到这一点，工具提示包括:https://www.w3schools.com/howto/tryit.asp?filename=tryhow_js_copy_clipboard2

如果使用React，一个很酷的想法是:使用Toastify提醒消息。 https://github.com/fkhadra/react-toastify这是一个很容易使用的库。 安装后，你可以更改这一行:

 alert(`Email copied: ${copyText.value} `)

比如:

toast.success(`Email Copied: ${copyText.value} `)

如果你想使用它，不要忘记安装toastify。导入ToastContainer，同时也导入css:

import { ToastContainer, toast } from "react-toastify"
import "react-toastify/dist/ReactToastify.css"

并将烤面包的容器放入里面返回。

import React from "react"

import { ToastContainer, toast } from "react-toastify"
import "react-toastify/dist/ReactToastify.css"


export default function Exemple() {
  function handleCopy() {
    var copyText = document.getElementById("mail")
    copyText.select()
    copyText.setSelectionRange(0, 99999)
    document.execCommand("copy")
    toast.success(`Hi! Now you can: ctrl+v: ${copyText.value} `)
  }

  return (
    <>
      <ToastContainer />
      <Container>
                <span>E-mail</span>
              <input
                readOnly
                type="text"
                value="myemail@exemple.com"
                id="mail"
              />
              <button onClick={handleCopy}>Copy Email</button>
      </Container>
    </>
  )
}

受@nate回答的启发，我创建了一个withCopyText反应钩子。并且，添加了navigator.clipboard.writeText支持execCommand回退。

钩子意味着它可以跨许多组件重用，而无需重复代码。有关实现，请参阅示例组件CopyText。

import React, { useRef, useState } from 'react';

const withCopyText = (textElementRef) => {
  if (!textElementRef) throw 'withCopyText: ref is required';

  const [copyStatus, setCopyStatus] = useState('');
  const [support, setSupport] = useState({
    navigatorClipboard: !!navigator.clipboard,
    exec: !!document.queryCommandSupported('copy'),
  });

  const copyToClipboard = (e) => {
    if ('' !== copyStatus) {
      setCopyStatus('');
      await new Promise((resolve) => setTimeout(resolve, 200));
    }

    // clipboard.writeText has wide but not 100% support
    // https://caniuse.com/?search=writeText
    if (support.navigatorClipboard) {
      try {
        navigator.clipboard.writeText(textElementRef.current.value);
        return setCopyStatus('success');
      } catch (e) {
        setSupport({ ...support, navigatorClipboard: false });
      }
    }
    // execCommand has > 97% support but is deprecated, use it as a fallback
    // https://caniuse.com/?search=execCommand
    // https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand
    if (!support.navigatorClipboard) {
      try {
        textElementRef.current.select();
        document.execCommand('copy');
        e.target.focus();
        setCopyStatus('success');
      } catch (e) {
        setSupport({ ...support, exec: false });
        return setCopyStatus('fail');
      }
    }
  };

  return {
    copyStatus,
    copyToClipboard,
    support: Object.values(support).includes(true),
  };
};

const CopyText = ({ text }) => {
  const textElementRef = useRef(null);

  const { copyStatus, copyToClipboard, support } = withCopyText(textElementRef);

  return (
    <span>
      {support && <button onClick={copyToClipboard}>Copy</button>}
      {'success' === copyStatus && <span>Copied to clipboard!</span>}
      {'fail' === copyStatus && <span>Sorry, copy to clipboard failed</span>}
      <input type="text" ref={textElementRef} value={text} readOnly={true} />
    </span>
  );
};

export { CopyText, withCopyText };

const handleCopy = async () => {
    let copyText = document.getElementById('input') as HTMLInputElement;
    copyText.select();
    document.execCommand('copy');
  };

return (
  <TextField
     variant="outlined"
     value={copyText}
     id="input" 
  />
);

这是我的工作。

我采取了和上面一些非常相似的方法，但我认为它更具体一些。在这里，父组件将作为道具传递url(或任何您想要的文本)。

import * as React from 'react'

export const CopyButton = ({ url }: any) => {
  const copyToClipboard = () => {
    const textField = document.createElement('textarea');
    textField.innerText = url;
    document.body.appendChild(textField);
    textField.select();
    document.execCommand('copy');
    textField.remove();
  };

  return (
    <button onClick={copyToClipboard}>
      Copy
    </button>
  );
};