Javascript: 实现复制内容到粘贴板, clipboardjs用法, 实现复制内容到剪贴板, How TO – Copy Text to Clipboard

1. 简单方法

HTML

<!-- The text field -->
<input type="text" value="Hello World" id="myInput">

<!-- The button used to copy the text -->
<button onclick="myFunction()">Copy text</button>

JavaScript

function myFunction() {
  /* Get the text field */
  var copyText = document.getElementById("myInput");

  /* Select the text field */
  copyText.select();

  /* Copy the text inside the text field */
  document.execCommand("Copy");

  /* Alert the copied text */
  alert("Copied the text: " + copyText.value);
}

DEMO: https://www.w3schools.com/howto/tryit.asp?filename=tryhow_js_copy_clipboard

2. 中级用法

HTML

<input id="copyTarget" value="Some initial text"> <button id="copyButton">Copy</button><br><br>
<span id="copyTarget2">Some Other Text</span> <button id="copyButton2">Copy</button><br><br>
<input id="pasteTarget"> Click in this Field and hit Ctrl+V to see what is on clipboard<br><br>
<span id="msg"></span><br>

JavaScript：

document.getElementById("copyButton").addEventListener("click", function() {
    copyToClipboardMsg(document.getElementById("copyTarget"), "msg");
});

document.getElementById("copyButton2").addEventListener("click", function() {
    copyToClipboardMsg(document.getElementById("copyTarget2"), "msg");
});

document.getElementById("pasteTarget").addEventListener("mousedown", function() {
    this.value = "";
});


function copyToClipboardMsg(elem, msgElem) {
	  var succeed = copyToClipboard(elem);
    var msg;
    if (!succeed) {
        msg = "Copy not supported or blocked.  Press Ctrl+c to copy."
    } else {
        msg = "Text copied to the clipboard."
    }
    if (typeof msgElem === "string") {
        msgElem = document.getElementById(msgElem);
    }
    msgElem.innerHTML = msg;
    setTimeout(function() {
        msgElem.innerHTML = "";
    }, 2000);
}

function copyToClipboard(elem) {
	  // create hidden text element, if it doesn't already exist
    var targetId = "_hiddenCopyText_";
    var isInput = elem.tagName === "INPUT" || elem.tagName === "TEXTAREA";
    var origSelectionStart, origSelectionEnd;
    if (isInput) {
        // can just use the original source element for the selection and copy
        target = elem;
        origSelectionStart = elem.selectionStart;
        origSelectionEnd = elem.selectionEnd;
    } else {
        // must use a temporary form element for the selection and copy
        target = document.getElementById(targetId);
        if (!target) {
            var target = document.createElement("textarea");
            target.style.position = "absolute";
            target.style.left = "-9999px";
            target.style.top = "0";
            target.id = targetId;
            document.body.appendChild(target);
        }
        target.textContent = elem.textContent;
    }
    // select the content
    var currentFocus = document.activeElement;
    target.focus();
    target.setSelectionRange(0, target.value.length);
    
    // copy the selection
    var succeed;
    try {
    	  succeed = document.execCommand("copy");
    } catch(e) {
        succeed = false;
    }
    // restore original focus
    if (currentFocus && typeof currentFocus.focus === "function") {
        currentFocus.focus();
    }
    
    if (isInput) {
        // restore prior selection
        elem.setSelectionRange(origSelectionStart, origSelectionEnd);
    } else {
        // clear temporary content
        target.textContent = "";
    }
    return succeed;
}

或者简单点， 用下面的也行：

function copyToClipboard(elem) {
	  // create hidden text element, if it doesn't already exist
    var targetId = "_hiddenCopyText_";
    var isInput = elem.tagName === "INPUT" || elem.tagName === "TEXTAREA";
    var origSelectionStart, origSelectionEnd;
    if (isInput) {
        // can just use the original source element for the selection and copy
        target = elem;
        origSelectionStart = elem.selectionStart;
        origSelectionEnd = elem.selectionEnd;
    } else {
        // must use a temporary form element for the selection and copy
        target = document.getElementById(targetId);
        if (!target) {
            var target = document.createElement("textarea");
            target.style.position = "absolute";
            target.style.left = "-9999px";
            target.style.top = "0";
            target.id = targetId;
            document.body.appendChild(target);
        }
        target.textContent = elem.textContent;
    }
    // select the content
    var currentFocus = document.activeElement;
    target.focus();
    target.setSelectionRange(0, target.value.length);
    
    // copy the selection
    var succeed;
    try {
    	  succeed = document.execCommand("copy");
    } catch(e) {
        succeed = false;
    }
    // restore original focus
    if (currentFocus && typeof currentFocus.focus === "function") {
        currentFocus.focus();
    }
    
    if (isInput) {
        // restore prior selection
        elem.setSelectionRange(origSelectionStart, origSelectionEnd);
    } else {
        // clear temporary content
        target.textContent = "";
    }
    return succeed;
}

DEMO: https://jsfiddle.net/jfriend00/v9g1x0o6/

来源：https://stackoverflow.com/a/22581382/4484798

3. 高级库 clipboardjs

主页：https://clipboardjs.com/

下载：clipboard.js-master

项目：https://github.com/zenorocha/clipboard.js

用法：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>constructor-nodelist</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
    <!-- 1. Define some markup -->
    <button data-clipboard-text="1">Copy</button>
    <button data-clipboard-text="2">Copy</button>
    <button data-clipboard-text="3">Copy</button>

    <!-- 2. Include library -->
    <script src="../dist/clipboard.min.js"></script>

    <!-- 3. Instantiate clipboard by passing a list of HTML elements -->
    <script>
    var btns = document.querySelectorAll('button');
    var clipboard = new ClipboardJS(btns);
    clipboard.on('success', function(e) {
        console.log(e);
    });
    clipboard.on('error', function(e) {
        console.log(e);
    });
    </script>
</body>
</html>

本文：Javascript: 实现复制内容到粘贴板, clipboardjs用法, 实现复制内容到剪贴板, How TO – Copy Text to Clipboard