定宽的textarea根据内容自动调整高度
程序员文章站
2022-06-10 11:45:42
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>固定textarea的宽度后，让textarea根据文本的长度自动调整它的高度。</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</head>
<body>
<br>
方法一：
<textarea rows=1 cols=40 style='overflow:scroll;overflow-y:hidden;overflow-x:hidden'
onfocus="window.activeobj=this;this.clock=setInterval(function(){activeobj.style.height=activeobj.scrollHeight+'px';},200);" onblur="clearInterval(this.clock);"></textarea>
<br><br>
方法二：
<script>
var agt = navigator.userAgent.toLowerCase();
var is_op = (agt.indexOf("opera") != -1);
var is_ie = (agt.indexOf("msie") != -1) && document.all && !is_op;
function ResizeTextarea(a,row){
if(!a){return}
if(!row)
row=5;
var b=a.value.split("\n");
var c=is_ie?1:0;
c+=b.length;
var d=a.cols;
if(d<=20){d=40}
for(var e=0;e<b.length;e++){
if(b[e].length>=d){
c+=Math.ceil(b[e].length/d)
}
}
c=Math.max(c,row);
if(c!=a.rows){
a.rows=c;
}
}
</script>
<textarea style="overflow: hidden; font-family: Verdana,Arial; font-style: normal; font-size: 13px; line-height: normal; " rows="4" cols="30" onfocus="javascript:ResizeTextarea(this,4);" onclick="javascript:ResizeTextarea(this,4);" onkeyup="javascript:ResizeTextarea(this,4);"></textarea>
<br><br>
方法三：
<script type="text/javascript">
//*2
var addHandler = window.addEventListener?
function(elem,event,handler){elem.addEventListener(event,handler);}:
function(elem,event,handler){elem.attachEvent("on"+event,handler);};
var $ = function(id){return document.getElementById(id);}
function autoTextArea(elemid){
//½һtextareaû߶
if(!$("_textareacopy")){
var t = document.createElement("textarea");
t.id="_textareacopy";
t.style.position="absolute";
t.style.left="-9999px";
document.body.appendChild(t);
}
function change(){
$("_textareacopy").value= $(elemid).value;
$(elemid).style.height= $("_textareacopy").scrollHeight+$("_textareacopy").style.height+"px";
}
addHandler($("target"),"propertychange",change);//for IE
addHandler($("target"),"input",change);// for !IE
$(elemid).style.overflow="hidden";//һأġ
$(elemid).style.resize="none";//ȥtextareaקŴ/С߶/ȹ
}
addHandler(window,"load",function(){
autoTextArea("target");
});
</script>
<textarea id="target" rows="" cols=""></textarea>
</body>
</html>