TextArea 控件的最大长度问题(js json)
2024-05-06 14:12:18
供稿：网友
如果只是单纯地想限制 textarea 中的字数，不想写太多的话，可用：
<textarea onkeyup="this.value = this.value.slice(0, 80)"></textarea>
或
<textarea onkeyup="this.value = this.value.substring(0, 80)"></textarea>
在 textarea 的 onkeyup 中检查字数之方法：
代码如下:
<script language="javascript" type="text/javascript">
function DjCheckMaxlength(oInObj)
{
var iMaxLen = parseInt(oInObj.getAttribute('maxlength'));
var iCurLen = oInObj.value.length;
if ( oInObj.getAttribute && iCurLen > iMaxLen )
{
oInObj.value = oInObj.value.substring(0, iMaxLen);
}
} //@ END OF DjCheckMaxlength()
</script>
<textarea maxlength="80" onkeyup="return DjCheckMaxlength(this);"></textarea>
o 设定好自动去检查所有的 textarea 之方法：
代码如下:
<head>
<script language="javascript" type="text/javascript">
function DjTextArea_AddMaxlengthAttr()
{
var aX = document.getElementsByTagName('textarea');
for ( var iI = 0; aX.length > iI; iI++ )
{
if ( aX[iI].getAttribute('maxlength') )
{
aX[iI].onkeyup = aX[iI].onchange = DjTextArea_CheckMaxlength;
}
}
} //@ END OF DjTextArea_AddMaxlengthAttr()
function DjTextArea_CheckMaxlength()
{
var iMaxLen = parseInt(this.getAttribute('maxlength'));
var iCurLen = this.value.length;
if ( this.getAttribute && iCurLen > iMaxLen )
{
this.value = this.value.substring(0, iMaxLen);
}
} //@ END OF DjTextArea_CheckMaxlength()
</script>
</head>
<body onload="DjTextArea_AddMaxlengthAttr();">
代码如下:
var Inputs = {
OnIntegerOnly: function() {
var k = System.isIE ? event.keyCode : event.which;
if(event.ctrlKey || event.ctrlAlt || event.shiftKey) {
Inputs.DisableInput(event);
return;
}
if ( ( k < 48 || k > 57 )
&& 8 != k
&& 9 != k
&& 46 != k
&& 37 != k
&& 39 != k
&& 16 != k
&& 36 != k
&& 35 != k
&& 17 != k
&& 13 != k
&& ( k < 96 || k > 105 )
) {
Inputs.DisableInput(event);
}
return k;
},
OnDecimalOnly: function() {
var k = System.isIE ? event.keyCode : event.which;
if(event.ctrlKey || event.ctrlAlt || event.shiftKey) {
Inputs.DisableInput(event);
return;
}
if( ( k < 48 || k > 57 )
&& 8 != k
&& 9 != k
&& 46 != k
&& 37 != k
&& 39 != k
&& 16 != k
&& 36 != k
&& 35 != k
&& 17 != k
&& 13 != k
&& 190 != k
&& 110 != k
&& ( k < 96 || k > 105 )
) {
Inputs.DisableInput(event);
}
return k;
},
OnAsciiOnly: function() {
var k = System.isIE ? event.keyCode : event.which;
if ( ( k < 97 || k > 122 )
&& ( k < 65 || k > 90 )
&& ( k < 48 || k > 57 )
&& 8 != k
&& 9 != k
&& 46 != k
