有没有办法订阅 window.getSelection 的变化？

Question

我们可以通过 获得一个选择范围window.getSelection()。我想知道是否有办法订阅window.getSelection更改。

我想到的唯一方法是使用超时（这显然很糟糕）或订阅每个用户的键\鼠标按下事件并手动跟踪更改。

Answer 1

使用onselect事件。function logSelection(event) {  const log = document.getElementById('log');  const selection = event.target.value.substring(event.target.selectionStart, event.target.selectionEnd);  log.textContent = `You selected: ${selection}`;}const textarea = document.querySelector('textarea');textarea.onselect = logSelection;<textarea>Try selecting some text in this element.</textarea><p id="log"></p>对于特定情况，例如span contenteditable，您可以制作一个 polyfill：function logSelection() {  const log = document.getElementById('log');  const selection = window.getSelection();  log.textContent = `You selected: ${selection}`;}const span = document.querySelector('span');var down = false;span.onmousedown = () => { down = true };span.onmouseup = () => { down = false };span.onmousemove = () => {  if (down == true) {    logSelection();  }};<span contenteditable="true">Try selecting some text in this element.</span><p id="log"></p>

Answer 2

如果我以正确的方式取消描述，你想知道用户何时开始在页面上进行选择，你可以使用 DOM onselectstart。document.onselectstart = function() {   console.log("Selection started!"); };