js实现在文本框光标处添加字符的方法介绍

代码如下:

<script language="javascript" type="text/javascript">
function Button4_onclick(obj) {
obj.focus();
var rng=document.selection.createRange();
rng.setEndPoint("StartToStart",obj.createTextRange());
var eng=document.selection.createRange();
eng.setEndPoint("EndToEnd",obj.createTextRange());
var kone = document.getElementByIdx("Text1");
kone.value=rng.text + "插入字符" + eng.text;
}
</script>
<input id="Text1" type="text" value="1235467890"/>
<input id="Button4" type="button"
value="button" onclick="return Button4_onclick(Text1)" />

代码如下:

<%@ Page Language="C#" AutoEventWireup="true" AspCompat="true" CodeBehind="WebForm1.aspx.cs"
Inherits="SJLERP.WebForm1" %>
<!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">
<script type="text/javascript">
function setCaret(textObj) {
if (textObj.createTextRange) {
textObj.caretPos = document.selection.createRange().duplicate();
}
}
function insertAtCaret(textObj, textFeildValue) {
if (document.all) {
if (textObj.createTextRange && textObj.caretPos) {
var caretPos = textObj.caretPos;
caretPos.text = caretPos.text.charAt(caretPos.text.length - 1) == ' ' ? textFeildValue + ' ' : textFeildValue;
} else {
textObj.value = textFeildValue;
}
} else {
if (textObj.setSelectionRange) {
var rangeStart = textObj.selectionStart;
var rangeEnd = textObj.selectionEnd;
var tempStr1 = textObj.value.substring(0, rangeStart);
var tempStr2 = textObj.value.substring(rangeEnd);
textObj.value = tempStr1 + textFeildValue + tempStr2;
} else {
alert("This version of Mozilla based browser does not support setSelectionRange");
}
}
}
</script>
<form id="form1" action="" onsubmit="" method="post" enctype="text/plain">
<p>
<textarea name="tarea" rows="" cols="" style="width:300px;height:120px;"
onselect="setCaret(this);"
onclick="setCaret(this);"
onkeyup="setCaret(this);" >例子例子例 Forget Never 子例子例子 asp.net </textarea>
<br/><br/>
<input type="text" name="textfield" style="width:220px;" value="插入FireFox"/>
<br/>
<input type="button" value="插入"
onclick="insertAtCaret(this.form.tarea,this.form.textfield.value);"/>
</p>
</form>
</html>