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[Java教程]js操作textarea方法集合


<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>js操作textarea方法集合</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">

<style type="text/css">
#testlujun {
width: 348px;
height: 80px;
border: #ddd 1px solid;
background: #fafafa;
padding: 5px 10px;
outline: none;
resize: none;
}

</style>
<body>
<textarea id="testlujun">abcdefghijklmnopqrstuvwxyz</textarea>
<br>
<input onclick="alert(TT.getCursorPosition(test))" type="button" value="光标位置">
<input onclick="TT.setCursorPosition(test,3)" type="button" value="设置光标到第3位置">
<input onclick="TT.add(test,'你好')" type="button" value="添加'你好'到光标后面">
<input onclick="TT.del(test,2)" type="button" value="删除光标前2个字符">
<input onclick="TT.del(test,-2)" type="button" value="删除光标后2个字符">
<input onclick="TT.sel(test,0,2)" type="button" value="选中字符0-2的位置">
<input onclick="TT.selString(test,'mno')" type="button" value="选中字符'mno'的位置">
</body>
<script type="text/javascript">
// <![CDATA[
var test = document.getElementById('testlujun');
var TT = {
/*
* 获取光标位置
* @Method getCursorPosition
* @param t element
* @return number
*/
getCursorPosition: function(t) {
if (document.selection) {
t.focus();
var ds = document.selection;
var range = ds.createRange();
var stored_range = range.duplicate();
stored_range.moveToElementText(t);
stored_range.setEndPoint("EndToEnd", range);
t.selectionStart = stored_range.text.length - range.text.length;
t.selectionEnd = t.selectionStart + range.text.length;
return t.selectionStart;
} else {
return t.selectionStart;
}
},

/*
* 设置光标位置
* @Method setCursorPosition
* @param t element
* @param p number
* @return
*/
setCursorPosition: function(t, p) {
this.sel(t, p, p);
},

/*
* 插入到光标后面
* @Method add
* @param t element
* @param txt String
* @return
*/
add: function(t, txt) {
var val = t.value;
if (document.selection) {
t.focus();
document.selection.createRange().text = txt;
} else {
var cp = t.selectionStart;
var ubbLength = t.value.length;
var s = t.scrollTop;
// document.getElementById('aaa').innerHTML += s + '<br />';
t.value = t.value.slice(0, t.selectionStart) + txt + t.value.slice(t.selectionStart, ubbLength);
this.setCursorPosition(t, cp + txt.length);
// document.getElementById('aaa').innerHTML += t.scrollTop + '<br />';
firefox = navigator.userAgent.toLowerCase().match(/firefox\/([\d\.]+)/) && setTimeout(function() {
if (t.scrollTop != s) t.scrollTop = s;
},
0)

};
},

/*
* 删除光标 前面或者后面的 n 个字符
* @Method del
* @param t element
* @param n number n>0 后面 n<0 前面
* @return
* 重新设置 value 的时候 scrollTop 的值会被清0
*/
del: function(t, n) {
var p = this.getCursorPosition(t);
var s = t.scrollTop;
var val = t.value;
t.value = n > 0 ? val.slice(0, p - n) + val.slice(p) : val.slice(0, p) + val.slice(p - n);
this.setCursorPosition(t, p - (n < 0 ? 0 : n));
firefox = navigator.userAgent.toLowerCase().match(/firefox\/([\d\.]+)/) && setTimeout(function() {
if (t.scrollTop != s) t.scrollTop = s;
},
10)
},

/*
* 选中 s 到 z 位置的文字
* @Method sel
* @param t element
* @param s number
* @param z number
* @return
*/
sel: function(t, s, z) {
if (document.selection) {
var range = t.createTextRange();
range.moveEnd('character', -t.value.length);
range.moveEnd('character', z);
range.moveStart('character', s);
range.select();
} else {
t.setSelectionRange(s, z);
t.focus();
}

},

/*
* 选中一个字符串
* @Method sel
* @param t element
* @param s String
* @return
*/
selString: function(t, s) {
var index = t.value.indexOf(s);
index != -1 ? this.sel(t, index, index + s.length) : false;
}

}
// ]]>
</script>
</html>