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光标定位：
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<meta http-equiv="content-type" content="text/html; charset=gb2312">
<meta name="generator" content="microsoft frontpage 4.0">
<meta name="progid" content="frontpage.editor.document">
<title>光标位置</title>
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input{border: 1 solid #000000}
body,table{font-size: 10pt}
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<table border="0" width="700" cellspacing="0" cellpadding="0">
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点击 textarea 实现光标定位
<p>
<textarea rows="7" cols="49" id="box" onclick=tellpoint()>我怕来不及我要抱着你，直到感觉你的绉纹有了岁月的痕迹，直到视线变得模糊直到不能呼吸
为了你我愿意
动也不能动也要看着你，直到感觉你的发线有了白雪的痕迹，直到肯定你是真的直到失去力气让我们形影不离
如果全世界我也能放弃，至少更有你值得我去珍惜而你在这里就是生命的奇迹
也许全世界我也能忘记，就是不愿意失去你的消息你掌心的痣我总记得在哪里
我们好不容易我们身不由已，我怕时间太快不够将你看仔细，我怕时间太慢日夜担心失去你恨不得一夜之间白头永不分离
</textarea>
<script>
function movepoint()
{
var pn = parseInt(pnum.value);
if(isNaN(pn))
return;
var rng = box.createTextRange();
rng.moveStart("character",pn);
rng.collapse(true);
rng.select();
returncase(rng);
}
function tellpoint()
{
var rng = event.srcElement.createTextRange();
rng.moveToPoint(event.x,event.y);
rng.moveStart("character",-event.srcElement.value.length);
pnum.value = rng.text.length;
returncase(rng);
}
function returncase(rng)
{
bh.innerText = rng.boundingHeight;
bl.innerText = rng.boundingLeft;
bt.innerText = rng.boundingTop;
bw.innerText = rng.boundingWidth;
ot.innerText = rng.offsetTop;
ol.innerText = rng.offsetLeft;
t.innerText = rng.text;
}
function selecttext(sp,ep)
{
sp = parseInt(sp);
ep = parseInt(ep);
if(isNaN(sp)||isNaN(ep))
return;
var rng = box.createTextRange();
rng.moveEnd("character",-box.value.length);
rng.moveStart("character",-box.value.length);
rng.collapse(true);
rng.moveEnd("character",ep);
rng.moveStart("character",sp);
rng.select();
returncase(rng);
}
function findtext(tw)
{
sw = document.selection.createRange().text.length;
var rg = box.createTextRange();
rg.moveEnd("character",box.value.length);
rg.moveStart("character",sw);
if(rg.findText(tw))
{
rg.select();
returncase(rg);
}
if(rg.text!=tw)
{
alert("已搜索完成，未发现此内容")
rg = box.createTextRange()
}
}
</script>
</p>
<p></p>
光标位置：<input type="text" value="0" id="pnum" size="8"> <input type="button" onClick="movepoint()" value="移动光标到指定位置">
<p></p>
选择指定范围：<input type="text" size="9" id="sbox"> -- <input type="text" size="9" id="ebox"> <input type="button" onClick="selecttext(sbox.value,ebox.value)" value="选择">
<p></p>
选择查找字符 ：<input type="text" value="" id="cbox" size="8"> <input type="button" onClick="findtext(cbox.value)" value="查找下一个并选择">
</td>
<td width="217">boundingheight: <span id="bh"></span></td>
</tr>
<tr>
<td width="217">boundingwidth: <span id="bw"></span></td>
</tr>
<tr>
<td width="217">boundingtop: <span id="bt"></span></td>
</tr>
<tr>
<td width="217">boundingleft: <span id="bl"></span></td>
</tr>
<tr>
<td width="217">offsetleft: <span id="ol"></span> </td>
</tr>
<tr>
<td width="217">offsettop: <span id="ot"></span> </td>
</tr>
<tr>
<td width="217">text: <span style="position: absolute; z-index: 10" id="t"></span> </td>
</tr>
</table>
</body>
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