如何在textarea中显示选定文本下方的div？
我有一个场景，我需要在文本区域中显示一个div（如弹出窗口）选择文本。但是，我使用鼠标按下它，div的位置有时不完全低于文本。
JavaScript的：
function getSel() { // obtain the object reference for the textarea> var txtarea = document.getElementById("mytextarea"); // obtain the index of the first selected character var start = txtarea.selectionStart; // obtain the index of the last selected character var finish = txtarea.selectionEnd; //obtain all Text var allText = txtarea.value; // obtain the selected text var sel = allText.substring(start, finish); sel = sel.replace(/[\S]/g, "*"); //append te text; var newText = allText.substring(0, start) + sel + allText.substring(finish, allText.length); txtarea.value = newText; $('#newpost').offset({ top: 0, left: 0 }).hide(); } $(document).ready(function () { var position; $('#newpost').hide(); $('#mytextarea').on('select', function (e) { var str = $('#mytextarea').val(); $('#newpost').offset(position).show(); var txtarea = document.getElementById("mytextarea"); var start = txtarea.selectionStart; var finish = txtarea.selectionEnd; $('#newpost div').text('Replace with stars'); }).on('select', function (e) { position = { top: e.pageY+10, left: e.pageX }; }); $('#newpost').hide(); }); function closePopUp() { $('#newpost').hide(); } 这是我的plunker链接
这里我的要求是显示文本的div选择。但是当我使用on-select而不是mouse-down时，div显示在text-area下面。
提前致谢。
几天前，在这个答案中，我提出了一种方法，即当用户选择一些文本时，找到光标位置并在textarea上显示div 。
然而，这种方法有效，正如@anub所提到的， div有时显示在所选文本的正下方，但是上下两个像素 – 因为它的位置是根据第一个用户的点击确定的。
经过短暂的搜索后 ，我发现这篇文章描述了如何通过创建给定textarea的临时div克隆来查找textarea中所选文本的位置。
我从那里采用了getCursorXY方法并用它来定位弹出窗口。
试试看！
function getSel() { // obtain the object reference for the textarea> var txtarea = document.getElementById("mytextarea"); // obtain the index of the first selected character var start = txtarea.selectionStart; // obtain the index of the last selected character var finish = txtarea.selectionEnd; //obtain all Text var allText = txtarea.value; // obtain the selected text var sel = Array(finish - start + 1).join("*"); //append te text; var newText = allText.substring(0, start) + sel + allText.substring(finish, allText.length); txtarea.value = newText; $('#newpost').offset({top: 0, left: 0}).hide(); } function closePopUp() { $('#newpost').offset({top: 0, left: 0}).hide(); } $(document).ready(function () { closePopUp(); var newpost = $('#newpost'); $('#mytextarea').on('select', function (e) { var txtarea = document.getElementById("mytextarea"); var start = txtarea.selectionStart; var finish = txtarea.selectionEnd; newpost.offset(getCursorXY(txtarea, start, 20)).show(); newpost.find('div').text(Array(finish - start + 1).join("*")); }); }); const getCursorXY = (input, selectionPoint, offset) => { const { offsetLeft: inputX, offsetTop: inputY, } = input // create a dummy element that will be a clone of our input const div = document.createElement('div') // get the computed style of the input and clone it onto the dummy element const copyStyle = getComputedStyle(input) for (const prop of copyStyle) { div.style[prop] = copyStyle[prop] } // we need a character that will replace whitespace when filling our dummy element // if it's a single line const swap = '.' const inputValue = input.tagName === 'INPUT' ? input.value.replace(/ /g, swap) : input.value // set the div content to that of the textarea up until selection const textContent = inputValue.substr(0, selectionPoint) // set the text content of the dummy element div div.textContent = textContent if (input.tagName === 'TEXTAREA') div.style.height = 'auto' // if a single line input then the div needs to be single line and not break out like a text area if (input.tagName === 'INPUT') div.style.width = 'auto' // create a marker element to obtain caret position const span = document.createElement('span') // give the span the textContent of remaining content so that the recreated dummy element // is as close as possible span.textContent = inputValue.substr(selectionPoint) || '.' // append the span marker to the div div.appendChild(span) // append the dummy element to the body document.body.appendChild(div) // get the marker position, this is the caret position top and left relative to the input const { offsetLeft: spanX, offsetTop: spanY } = span // lastly, remove that dummy element // NOTE:: can comment this out for debugging purposes if you want to see where that span is rendered document.body.removeChild(div) // return an object with the x and y of the caret. account for input positioning // so that you don't need to wrap the input return { left: inputX + spanX, top: inputY + spanY + offset, } }
#mytextarea {width: 600px; height: 200px; overflow:hidden; position:fixed} #newpost { position:absolute; background-color:#ffffdc; border:1px solid #DCDCDC; border-radius:10px; padding-right:5px; width: auto; height: 30px; } #newpost span { cursor:pointer; position: absolute; top: 0; right: 5px; font-size: 22px; } #newpost div { color:#0000ff; padding:10px; margin-right:10px; width: auto; cursor:pointer; }
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我在关闭弹出窗口并重新选择另一个区域时遇到了这个问题，我解决了这个问题
function closePopUp() { $('#newpost').offset({ top: 0, left: 0 }).hide(); }
看一下这个