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>
    </>
  )
}

剪贴板将在2021年得到各大浏览器的良好支持。一种方法是首先构建剪贴板函数的副本，然后使用onClick事件处理程序调用它。

function copy(text){
  navigator.clipboard.writeText(text)
}

为了防止硬编码，让我们假设字符串被分配给一个名为someText的变量

<span onClick={() => copy(someText)}>
  {someText}
</span>

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);
}

您可以使用useRef选择元素中的文本，然后将其复制到剪贴板

import React, { useRef } from "react";

const Comp = () => {
   const copyTxt = useRef();

   const handleCopyTxt = () => {
   let txtDiv = copyTxt.current;
      if (document.selection) {
        // IE
        var range = document.body.createTextRange();
        range.moveToElementText(txtDiv);
        range.select();
      } else if (window.getSelection) {
        // other browsers
        var range = document.createRange();
        range.selectNode(txtDiv);
        window.getSelection().removeAllRanges();
        window.getSelection().addRange(range);
      }
      document.execCommand("copy");
    }

    return ( <div ref={copyTxt} > some text to copied </div> )
}

如果希望从DIV而不是文本字段中进行选择，下面是代码。“代码”是需要复制的值

import React from 'react'
class CopyToClipboard extends React.Component {

  copyToClipboard(code) {
    var textField = document.createElement('textarea')
    textField.innerText = code
    document.body.appendChild(textField)
    textField.select()
    document.execCommand('copy')
    textField.remove()
  }
  render() {
    return (
      <div onClick={this.copyToClipboard.bind(this, code)}>
        {code}
      </div>

    )
  }
}

export default CopyToClipboard

对于那些试图从DIV而不是文本字段中进行选择的人，下面是代码。代码是不言自明的，但如果你想了解更多信息，请在这里评论:

     import React from 'react';
     ....

    //set ref to your div
          setRef = (ref) => {
            // debugger; //eslint-disable-line
            this.dialogRef = ref;
          };

          createMarkeup = content => ({
            __html: content,
          });

    //following function select and copy data to the clipboard from the selected Div. 
   //Please note that it is only tested in chrome but compatibility for other browsers can be easily done

          copyDataToClipboard = () => {
            try {
              const range = document.createRange();
              const selection = window.getSelection();
              range.selectNodeContents(this.dialogRef);
              selection.removeAllRanges();
              selection.addRange(range);
              document.execCommand('copy');
              this.showNotification('Macro copied successfully.', 'info');
              this.props.closeMacroWindow();
            } catch (err) {
              // console.log(err); //eslint-disable-line
              //alert('Macro copy failed.');
            }
          };

              render() {
                    return (
                        <div
                          id="macroDiv"
                          ref={(el) => {
                            this.dialogRef = el;
                          }}
                          // className={classes.paper}
                          dangerouslySetInnerHTML={this.createMarkeup(this.props.content)}
                        />
                    );
            }