纯JS，没有内联onclick，配对类“内容-复制按钮”。如果你有很多元素，会更舒服)

(function(){ /* Creating textarea only once, but not each time */ let area = document.createElement('textarea'); document.body.appendChild( area ); area.style.display = "none"; let content = document.querySelectorAll('.js-content'); let copy = document.querySelectorAll('.js-copy'); for( let i = 0; i < copy.length; i++ ){ copy[i].addEventListener('click', function(){ area.style.display = "block"; /* because the classes are paired, we can use the [i] index from the clicked button, to get the required text block */ area.value = content[i].innerText; area.select(); document.execCommand('copy'); area.style.display = "none"; /* decorative part */ this.innerHTML = 'Cop<span style="color: red;">ied</span>'; /* arrow function doesn't modify 'this', here it's still the clicked button */ setTimeout( () => this.innerHTML = "Copy", 2000 ); }); } })(); hr { margin: 15px 0; border: none; } <span class="js-content">1111</span> <button class="js-copy">Copy</button> <hr> <span class="js-content">2222</span> <button class="js-copy">Copy</button> <hr> <span class="js-content">3333</span> <button class="js-copy">Copy</button>

旧的浏览器支持:

(function(){ var area = document.createElement('textarea'); document.body.appendChild( area ); area.style.display = "none"; var content = document.querySelectorAll('.js-content'); var copy = document.querySelectorAll('.js-copy'); for( var i = 0; i < copy.length; i++ ){ copyOnClick(i); } function copyOnClick(i){ copy[i].addEventListener('click', function(){ area.style.display = "block"; area.value = content[i].innerText; area.select(); document.execCommand('copy'); area.style.display = "none"; var t = this; t.innerHTML = 'Cop<span style="color: red;">ied</span>'; setTimeout( function(){ t.innerHTML = "Copy" }, 2000 ); }); } })(); hr { margin: 15px 0; border: none; } <span class="js-content">1111</span> <button class="js-copy">Copy</button> <hr> <span class="js-content">2222</span> <button class="js-copy">Copy</button> <hr> <span class="js-content">3333</span> <button class="js-copy">Copy</button>

这里是HTML代码

    <input id="result" style="width:300px"/>some example text
    <button onclick="copyToClipboard('result')">Copy P1</button>
    <input type="text" style="width:400px" placeholder="Paste here for test" />

JS代码:

     function copyToClipboard(elementId) {

                      // Create a "hidden" input
                      var aux = document.createElement("input");

                      aux.setAttribute("value", document.getElementById(elementId).value);
                      // Append it to the body
                      document.body.appendChild(aux);
                      // Highlight its content
                      aux.select();
                      // Copy the highlighted text
                      document.execCommand("copy");
                      // Remove it from the body
                      document.body.removeChild(aux);
                    }

2022年6月

更新:现在正确的方法是使用剪贴板API。

例如:

// get the text from the DOM Element: 
const textToCopy = document.querySelector('.content').innerText

// when someone clicks on the <a class="copy-text"> element 
// (which should be a <button>), execute the copy command:
document.querySelector('.copy-text').addEventListener('click' , ()=> {
  navigator.clipboard.writeText(textToCopy).then(
    function() {
      /* clipboard successfully set */
      window.alert('Success! The text was copied to your clipboard') 
    }, 
    function() {
      /* clipboard write failed */
      window.alert('Opps! Your browser does not support the Clipboard API')
    }
  )
})

就是这样。

如果你想看看在Clipboard API引入之前的解决方案(现在不是一个好的实践):

$('button.copyButton').click(function(){
    $(this).siblings('input.linkToCopy').select();      
    document.execCommand("copy");
});

HTML:

<button class="copyButton">click here to copy</button>
<input class="linkToCopy" value="TEXT TO COPY"
style="position: absolute; z-index: -999; opacity: 0;" />

你为什么不直接用这个代码，我不明白?

navigator.clipboard.writeText('text here...');

这是一个优雅的Javascript解决方案

<input type="text" value="Foo Bar" id="your_input">
<button onclick="copy()">Copy text</button>

<script type="application/javascript">
function copy() {
  var copiedtext = document.getElementById("your_input");
  copiedtext.select();
  copiedtext.setSelectionRange(0, 99999); //for mobile devices
  navigator.clipboard.writeText(copiedtext.value);
  alert("You just copied " + copiedtext.value);
}
</script>

换行(阿尔瓦罗·蒙托罗回答的延伸)

var ClipboardHelper = {

    copyElement: function ($element)
    {
       this.copyText($element.text())
    },
    copyText:function(text) // Linebreaks with \n
    {
        var $tempInput =  $("<textarea>");
        $("body").append($tempInput);
        $tempInput.val(text).select();
        document.execCommand("copy");
        $tempInput.remove();
    }
};

ClipboardHelper.copyText('Hello\nWorld');
ClipboardHelper.copyElement($('body h1').first());