如何从文本区域中突出显示的文本中获取邻居字符？
[英]How to get neighbor character from highlighted text in the textarea?
问题描述
This returns highlighted text: 
这将返回突出显示的文本：
function getSelection(elem) { var selectedText; if (document.selection != undefined) { // IE elem.focus(); var sel = document.selection.createRange(); selectedText = sel.text; } else if (elem.selectionStart != undefined) { // Firefox var startPos = elem.selectionStart; var endPos = elem.selectionEnd; selectedText = elem.value.substring(startPos, endPos) } return selectedText; } $(document).on('mousedown', 'button', function(e) { var selection = getSelection( $('#txtarea').get(0) ); alert(selection); });
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <textarea id="txtarea">this is a test</textarea> <button>highlighted text</button>
Now I need to select adjacent character from selected/highlighted text. 现在，我需要从选中/突出显示的文本中选择相邻字符。 for example if his is at is selected, then I need to get both t (L) and e (R) characters. 例如，如果选择his is at ，则我需要同时获取t （L）和e （R）字符。 How can I do that? 我怎样才能做到这一点？
2 个解决方案
解决方案1
0 2016-01-18 04:27:50
Get the value of the textarea using 使用获取文本区域的值
var preview=document.getElementById("txtarea");
Get it's content using 使用获取内容
var str=preview.value
The string to be matched 要匹配的字符串
x="his is a t"
Using indexOf to get the character at which it starts 使用indexOf获取开始的字符
res=str.indexOf(x)
this returns 1 这将返回1
To find the character before it(check for res!=0) 要找到它之前的字符（检查res！= 0）
str.charAt(res-1)
Returns "t" 返回“ t”
For the last char 对于最后一个字符
str.charAt(res+x.length)
Returns "e" 返回“ e”
解决方案2
0 已采纳 2016-01-18 04:40:09
Try this one 试试这个
function GetSelection() { var selection = ""; var textarea = document.getElementById("myArea"); if ('selectionStart' in textarea) { // check whether some text is selected in the textarea if (textarea.selectionStart != textarea.selectionEnd) { selection = textarea.value.substring(textarea.selectionStart - 1, textarea.selectionEnd + 1); } } else { // Internet Explorer before version 9 // create a range from the current selection var textRange = document.selection.createRange(); // check whether the selection is within the textarea var rangeParent = textRange.parentElement(); if (rangeParent === textarea) { selection = textRange.text; } } if (selection == "") { alert("No text is selected."); } else { alert("The current selection is: " + selection); } }
<body> <textarea id="myArea" spellcheck="false">Select some text within this field.</textarea> <button onclick="GetSelection ()">Get the current selection</button> </body>
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