限制textarea的字符数

限制textarea的字符数 </p> <p>var TextUtil = new Object(); TextUtil.isNotMax = function(oTextArea) { return oTextArea.value.length != oTextArea.getAttribute("maxlength"); } </p> <p><textarea cols="85" rows="15" name="code" class="javascript">var comment_max_length = 170; function checkInputLength(obj) { var _text = obj.value; var max_length = comment_max_length; if(event.keyCode==8 || event.keyCode==46){ event.returnValue = true; } else { if(obj.value.length > max_length) { event.returnValue = false; document.saveForm.save.focus(); obj.value = _text.substring(0, max_length); } } } function SetTextAreaMaxLength(controlId,length) { function doBeforePaste(control,length){ maxLength = length; if(maxLength) { event.returnValue = false; } } function doPaste(control,length){ maxLength = length; value = control.value; if(maxLength){ event.returnValue = false; maxLength = parseInt(maxLength); var oTR = control.document.selection.createRange(); var iInsertLength = maxLength - value.length + oTR.text.length; var sData = window.clipboardData.getData("Text").substr(0,iInsertLength); oTR.text = sData; } } function doDragenter(control,length){ maxLength = length; value = control.value; if(maxLength){ event.returnValue = false; } } function addEvent(elm, evType, fn, useCapture) { if (elm.addEventListener) { elm.addEventListener(evType, fn, useCapture); return true; } else if (elm.attachEvent) { var r = elm.attachEvent('on' + evType, fn); return r; } else { elm['on' + evType] = fn; } } function AttacheventTextAreaBeforePaste(obj,length) { return function() { doBeforePaste(obj,length) } } function AttacheventTextAreaPaste(obj,length) { return function() { doPaste(obj,length) } } function AttacheventTextAreaDragEnter(obj,length) { return function() { doDragenter(obj,length); } } var obj = document.getElementById(controlId); addEvent(obj,'beforepaste',AttacheventTextAreaBeforePaste(obj,length),null); addEvent(obj,'paste',AttacheventTextAreaPaste(obj,length),null); addEvent(obj,'dragenter',AttacheventTextAreaDragEnter(obj,length),null); } <textarea name="draft_comment"id="draft_comment" rows="5" style="width:100%;" class="jp_default" οnkeypress="return checkInputLength(this);" οnkeydοwn="return checkInputLength(this);" οnkeyup="return checkInputLength(this);" οnfοcus="return checkInputLength(this);" οnchange="return checkInputLength(this);"><c:out value="${completeSheetInfoBean.comment}"/>