網上苦找2小時，全是不能兼容FF的，看來這種東西網上是搞不到現成的了，只能自己動手豐衣足食
現在發布出來，今後網上就有現成的供人使用了。
為了省事，少量位置用了jquery 改原生JS也很方便，誰需要就請自己修改了。
歡迎各位路過高人拍板，歡迎各位留言提供改進代碼。
又改進 兼容了Chrome 下面的代碼已修改成最新版
上源碼了
復制代碼 代碼如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>js獲取div編輯框，textarea，input text的光標位置，兼容FF和IE</title>
<script src="jquery-1.4.4.js" type="text/javascript"></script>
<script type="text/javascript">
//去除左右所有空格
String.prototype.trim = function () {
return this.replace(/(^\s*)|(\s*$)/g, "");
}
function getPosition(element) {
var OsObject = "";
if (navigator.userAgent.indexOf("MSIE") > 0) {
OsObject = "MSIE";
}
if (navigator.userAgent.indexOf("Firefox") > 0) {
OsObject = "Firefox";
}
if (navigator.userAgent.indexOf("Safari") > 0) {
OsObject = "Safari";
}
if (navigator.userAgent.indexOf("Camino") > 0) {
OsObject = "Camino";
}
if (navigator.userAgent.indexOf("Gecko") > 0) {
OsObject = "Gecko";
}
if (navigator.userAgent.indexOf("Chrome") > 0) {
OsObject = "Chrome";
}
var result = 0;
if (!document.selection) { //非IE浏覽器
var thisTagName = null;
if ($(element).attr("tagName") != "TEXTAREA" && $(element).attr("tagName") != "INPUT") {
if ($(element).attr("tagName") == "DIV" && $(element).attr("contenteditable") == "true") {
thisTagName = window.getSelection().anchorNode.parentElement.tagName;
} //出自http://www.cnblogs.com/ahjesus 尊重作者辛苦勞動成果，轉載請注明出處，謝謝！
else {
thisTagName == null;
}
}
else {
if ($(element).attr("tagName") == "INPUT" && $(element).attr("type") == "text") {
thisTagName = window.getSelection().anchorNode.tagName;
}
else {
console.log(window.getSelection());
thisTagName = window.getSelection().anchorNode.tagName;
}
}
console.log(thisTagName);
if (thisTagName == "TEXTAREA" || thisTagName == "INPUT" || (thisTagName=="BODY"&&OsObject == "Chrome")) {
result = element.selectionStart
} //出自http://www.cnblogs.com/ahjesus 尊重作者辛苦勞動成果，轉載請注明出處，謝謝！
else if (thisTagName != null) {
if (thisTagName == element.tagName) {
if (window.getSelection().anchorNode.textContent == $(element).text()) {
result = window.getSelection().anchorOffset;
}
else {
var currentIndex = window.getSelection().anchorOffset;
var txt = "";
var txtoo = window.getSelection().anchorNode.previousSibling;
while (txtoo != null) {
txt += txtoo.textContent;
txtoo = txtoo.previousSibling;
} //出自http://www.cnblogs.com/ahjesus 尊重作者辛苦勞動成果，轉載請注明出處，謝謝！
result = txt.trim().length + currentIndex;
}
}
else {
var currentIndex = window.getSelection().anchorOffset;
var txt = "";
var txtoo = window.getSelection().anchorNode.parentElement.previousSibling;
while (txtoo != null) {
txt += txtoo.textContent;
txtoo = txtoo.previousSibling;
}
result = txt.trim().length + currentIndex;
}
} //出自http://www.cnblogs.com/ahjesus 尊重作者辛苦勞動成果，轉載請注明出處，謝謝！
else {
return 0;
}
} else { //IE
var rng;
if ($(element).attr("tagName") == "TEXTAREA" || ($(element).attr("tagName") == "INPUT" && $(element).attr("type") == "text") || ($(element).attr("tagName") == "DIV" && $(element).attr("contenteditable") == "true")) {
element.focus();
rng = document.selection.createRange();
rng.moveStart('character', -element.innerText.length);
var text = rng.text;
for (var i = 0; i < element.innerText.length; i++) {
if (element.innerText.substring(0, i + 1) == text.substring(text.length - i - 1, text.length)) {
result = i + 1;
}
}
} //出自http://www.cnblogs.com/ahjesus 尊重作者辛苦勞動成果，轉載請注明出處，謝謝！
else {
return 0;
}
}
return result;
}
function getValue(element) {
var pos = getPosition(element);
document.getElementById("pnum").value = pos;
}
</script>
<style type="text/css">
#Div1, #Div2
{
width: 500px;
height: 100px;
border: solid 1px black;
}
</style>
</head>
<body>
<input id="pnum" type="text" value="Hello,wellcome to test! 你好,歡迎測試!" onmouseup="getValue(this)"
style="display: block" />
<textarea cols="60" rows="10" onkeyup="getValue(this)" onmouseup="getValue(this)">Hello,wellcome to test! 你好,歡迎測試! 注意源代碼開閉合標記之間不能換行，否則統計錯誤！</textarea>
<div id="Div1" onclick="getValue(this);" onkeyup="getValue(this);" contenteditable="true">一二三<span>四五</span>六七八<span>九零</span> 注意源代碼開閉合標記之間不能換行，否則統計錯誤！注意div編輯框源碼裡面是嵌套有其他標簽的，可以正常返回正確位置！</div>
<br />
<div id="Div2" onclick="getValue(this);" onkeyup="getValue(this);">一二三四五六<span>七八</span></div>
</body>
</html>