为textarea 增加 maxlength 属性
為 textarea 增加 maxlength 屬性
o 如果只是單純地想限制 textarea 中的字數，不想寫太多的話，可用：<textarea onkeyup="this.value = this.value.slice(0, 80)"></textarea>或<textarea onkeyup="this.value = this.value.substring(0, 80)"></textarea>o 在 textarea 的 onkeyup 中檢查字數之方法：.....<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 設定好自動去檢查所有的 textarea 之方法：.....<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();">.....