此解决方案比仅获取文本更进一步，它实际上允许您在将粘贴的内容粘贴到元素中之前对其进行编辑。
它通过使用 contenteditable、onpaste 事件（所有主流浏览器都支持）和突变观察者（Chrome、Firefox 和 IE11+ 支持）来工作
第一步
使用 contenteditable 创建一个 HTML 元素
<div contenteditable="true" id="target_paste_element"></div>
第 2 步
在您的 Javascript 代码中添加以下事件
document.getElementById("target_paste_element").addEventListener("paste", pasteEventVerifierEditor.bind(window, pasteCallBack), false);
我们需要绑定 pasteCallBack，因为突变观察者会被异步调用。
第 3 步
将以下函数添加到您的代码中
function pasteEventVerifierEditor(callback, e)
{
//is fired on a paste event.
//pastes content into another contenteditable div, mutation observer observes this, content get pasted, dom tree is copied and can be referenced through call back.
//create temp div
//save the caret position.
savedCaret = saveSelection(document.getElementById("target_paste_element"));
var tempDiv = document.createElement("div");
tempDiv.id = "id_tempDiv_paste_editor";
//tempDiv.style.display = "none";
document.body.appendChild(tempDiv);
tempDiv.contentEditable = "true";
tempDiv.focus();
//we have to wait for the change to occur.
//attach a mutation observer
if (window['MutationObserver'])
{
//this is new functionality
//observer is present in firefox/chrome and IE11
// select the target node
// create an observer instance
tempDiv.observer = new MutationObserver(pasteMutationObserver.bind(window, callback));
// configuration of the observer:
var config = { attributes: false, childList: true, characterData: true, subtree: true };
// pass in the target node, as well as the observer options
tempDiv.observer.observe(tempDiv, config);
}
}
function pasteMutationObserver(callback)
{
document.getElementById("id_tempDiv_paste_editor").observer.disconnect();
delete document.getElementById("id_tempDiv_paste_editor").observer;
if (callback)
{
//return the copied dom tree to the supplied callback.
//copy to avoid closures.
callback.apply(document.getElementById("id_tempDiv_paste_editor").cloneNode(true));
}
document.body.removeChild(document.getElementById("id_tempDiv_paste_editor"));
}
function pasteCallBack()
{
//paste the content into the element.
restoreSelection(document.getElementById("target_paste_element"), savedCaret);
delete savedCaret;
pasteHtmlAtCaret(this.innerHTML, false, true);
}
saveSelection = function(containerEl) {
if (containerEl == document.activeElement)
{
var range = window.getSelection().getRangeAt(0);
var preSelectionRange = range.cloneRange();
preSelectionRange.selectNodeContents(containerEl);
preSelectionRange.setEnd(range.startContainer, range.startOffset);
var start = preSelectionRange.toString().length;
return {
start: start,
end: start + range.toString().length
};
}
};
restoreSelection = function(containerEl, savedSel) {
containerEl.focus();
var charIndex = 0, range = document.createRange();
range.setStart(containerEl, 0);
range.collapse(true);
var nodeStack = [containerEl], node, foundStart = false, stop = false;
while (!stop && (node = nodeStack.pop())) {
if (node.nodeType == 3) {
var nextCharIndex = charIndex + node.length;
if (!foundStart && savedSel.start >= charIndex && savedSel.start <= nextCharIndex) {
range.setStart(node, savedSel.start - charIndex);
foundStart = true;
}
if (foundStart && savedSel.end >= charIndex && savedSel.end <= nextCharIndex) {
range.setEnd(node, savedSel.end - charIndex);
stop = true;
}
charIndex = nextCharIndex;
} else {
var i = node.childNodes.length;
while (i--) {
nodeStack.push(node.childNodes[i]);
}
}
}
var sel = window.getSelection();
sel.removeAllRanges();
sel.addRange(range);
}
function pasteHtmlAtCaret(html, returnInNode, selectPastedContent) {
//function written by Tim Down
var sel, range;
if (window.getSelection) {
// IE9 and non-IE
sel = window.getSelection();
if (sel.getRangeAt && sel.rangeCount) {
range = sel.getRangeAt(0);
range.deleteContents();
// Range.createContextualFragment() would be useful here but is
// only relatively recently standardized and is not supported in
// some browsers (IE9, for one)
var el = document.createElement("div");
el.innerHTML = html;
var frag = document.createDocumentFragment(), node, lastNode;
while ( (node = el.firstChild) ) {
lastNode = frag.appendChild(node);
}
var firstNode = frag.firstChild;
range.insertNode(frag);
// Preserve the selection
if (lastNode) {
range = range.cloneRange();
if (returnInNode)
{
range.setStart(lastNode, 0); //this part is edited, set caret inside pasted node.
}
else
{
range.setStartAfter(lastNode);
}
if (selectPastedContent) {
range.setStartBefore(firstNode);
} else {
range.collapse(true);
}
sel.removeAllRanges();
sel.addRange(range);
}
}
} else if ( (sel = document.selection) && sel.type != "Control") {
// IE < 9
var originalRange = sel.createRange();
originalRange.collapse(true);
sel.createRange().pasteHTML(html);
if (selectPastedContent) {
range = sel.createRange();
range.setEndPoint("StartToStart", originalRange);
range.select();
}
}
}
代码的作用：
- 有人使用 ctrl-v、上下文菜单或其他方式触发粘贴事件
- 在粘贴事件中，创建了一个具有 contenteditable 的新元素（具有 contenteditable 的元素具有提升的权限）
- 目标元素的插入符号位置已保存。
- 焦点设置在新元素上
- 内容被粘贴到新元素中并在 DOM 中呈现。
- 突变观察者捕捉到了这一点（它记录了对 dom 树和内容的所有更改）。然后触发突变事件。
- 粘贴内容的 dom 被克隆到一个变量中并返回给回调。临时元素被销毁。
- 回调接收克隆的 DOM。插入符号已恢复。您可以在将其附加到目标之前对其进行编辑。元素。在此示例中，我使用 Tim Downs 函数来保存/恢复插入符号并将 HTML 粘贴到元素中。
非常感谢Tim Down