如何选取textarea的特定行

[ilovegc2]

如何选取textarea的特定行

[cuixiping]

<SCRIPT language="javascript">
function getTextRange(num, oTextarea)
{
var range = oTextarea.createTextRange();
var rect = range.getClientRects();
var left = rect[0].left;
if(num > rect.length - 1 || num < 0)
return;
if(num == 0)
{
var right = rect[0].right;

range.moveEnd("character",-range.text.length);
while(range.offsetLeft + range.boundingWidth < right)
{
range.expand("character");
}
}
else
{
var right = rect[num].right;

var range = getTextRange(num - 1, oTextarea);
range.moveStart("character",range.text.length + 1);
while(range.offsetLeft + range.boundingWidth < right)
{
range.expand("character");
}
if(range.offsetLeft > left)
{
range.moveStart("character",-1);
}
}
range.moveEnd("character",+1);
if(range.text.indexOf("\r")>=0)
{
range.moveEnd("character", range.text.indexOf("\r")-range.text.length+1);
}else{
range.moveEnd("character",-1);
}
return range;
}

function getText(num)
{
var range = getTextRange(num,Textarea1)
if(range != null)
{
range.select();
}
}
</SCRIPT>

<textarea cols="50" rows="10" id="Textarea1">
fsdasdasi
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaafsdasdasiaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
vsdasdasu
fsdasdasiaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
bsdasdasd
</textarea>

<br><br>

<input type="button" onClick="getText(0)" value="选第1行">
<input type="button" onClick="getText(1)" value="选第2行">
<input type="button" onClick="getText(2)" value="选第3行">
<input type="button" onClick="getText(3)" value="选第4行">
<br>
<input type="button" onClick="getText(4)" value="选第5行">
<input type="button" onClick="getText(5)" value="选第6行">
<input type="button" onClick="getText(6)" value="选第7行">
<input type="button" onClick="getText(7)" value="选第8行">

[softlead]

题目 好象不很明朗哦／？？