首頁 > 建站 > 前端技術

常用的JAVAscript限制輸入字元數代碼

來源：互聯網
上載者：User
關鍵字 網頁製作 Ajax JavaScript
創建阿里雲帳戶，並獲得超過 40 款產品的免費試用版；而企業帳戶則可以享有總值 $1200 的免費試用版。立即註冊！

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "HTTP://www.jzread.com/TR/xhtml1/DTD/ xhtml1-transitional.dtd">
<html xmlns="HTTP://www.jzread.com/1999/xhtml">
<head>
< meta HTTP-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css教程" media="screen">
body{ margin:0px; padding:0px;}
div{ width:400px; margin:0px auto;}
div h3{ background:#CCCCCC; font-size:14px; font-weight:bold; text-align:center; line-height:22px; margin:6px 0px; padding:0px;}
div textarea{ width:388px; height:120px; border:#999999 1px solid; margin:0px; padding:0px; font-size:12px; padding: 5px; line-height:16px;}
div p{ font-size:12px; margin:0px; line-height:22px;}
div p span{ color:#FF6600; font-weight:bold;}
</style>
<title>JAVAscript限制文字方塊輸入的最大字元數</title>
</head>

<body>
<div>
<h3>字元數測試</h3>
<textarea rows="20" cols="50" onkeypress="return checkMaxLength(this,20)"></textarea>
<p>最多<span>20</span>個字元。 </p>
</div>

<script type="text/javascript教程">
function checkMaxLength(oTextArea,maxLength){
return oTextArea.value.length!=maxLength;
}
</script>
</body>
</html>

方案二

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "HTTP://www.jzread.com/TR/xhtml1/DTD/ xhtml1-transitional.dtd">
<html xmlns="HTTP://www.jzread.com/1999/xhtml">
<head>
< meta HTTP-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css" media="screen">
body{ margin:0px; padding:0px;}
div{ width:400px; margin:0px auto;}
div h3{ background:#CCCCCC; font-size:14px; font-weight:bold; text-align:center; line-height:22px; margin:6px 0px; padding:0px;}
div textarea{ width:388px; height:120px; border:#999999 1px solid; margin:0px; padding:0px; font-size:12px; padding: 5px; line-height:16px;}
div p{ font-size:12px; margin:0px; line-height:22px;}
div p span{ color:#FF6600; font-weight:bold;}
</style>
<title>JAVAscript限制文字方塊輸入的最大字元數</title>
</head>

<body>
<div>
<h3>字元數測試</h3>
<textarea rows="20" cols="50" onkeyup="checkMaxLength(this,20)" onpaste="checkMaxLength(this,20)"></ textarea>
<p>最多<span>20</span>個字元。 </p>
</div>

<script type="text/javascript">
function checkMaxLength(area, maxLength) {
if (area.value.length >maxLength) {
area.value = area.value.substr(0, maxLength);
}
}
</script>
</body>
</html>

方案三

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "HTTP://www.jzread.com/TR/xhtml1/DTD/ xhtml1-transitional.dtd">
<html xmlns="HTTP://www.jzread.com/1999/xhtml">
<head>
< meta HTTP-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css" media="screen">
body{ margin:0px; padding:0px;}
div{ width:400px; margin:0px auto;}
div h3{ background:#CCCCCC; font-size:14px; font-weight:bold; text-align:center; line-height:22px; margin:6px 0px; padding:0px;}
div textarea{ width:388px; height:120px; border:#999999 1px solid; margin:0px; padding:0px; font-size:12px; padding: 5px; line-height:16px;}
div p{ font-size:12px; margin:0px; line-height:22px;}
div p span{ color:#FF6600; font-weight:bold;}
</style>
<title>JAVAscript限制文字方塊輸入的最大字元數</title>
</head>

<body>
<div>
<h3>字元數測試</h3>
<textarea rows="20" cols="50" onkeyup=" checkMaxLength(this,20)" onpaste="checkMaxLength(this,20)"></textarea>
<p>最多<span>20 </span>個字元，一個漢字2個字元。 </p>
</div>

<script type="text/javascript">
function checkMaxLength(area, maxLength) {
       var currentStr="";
      for(var i=0,len=area.value.length;i<len;i++) {
            currentStr+=area.value.charAt(i);
           if(getCharLength(currentStr)>maxLength){
                  area.value=area.value.substr(0,i);
                    return;
           }
     }
}

function getCharLength(str){
var charLen=0;
for(var i=0,len=str.length;i<len;i++){
if(str.charCodeAt(i)>255){
charLen+=2;
}else{
charLen+=1;
}
}
return charLen;
}
</script>
</body>
</html>

方案三

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "HTTP://www.jzread.com/TR/xhtml1/DTD/ xhtml1-transitional.dtd">
<html xmlns="HTTP://www.jzread.com/1999/xhtml">
<head>
< meta HTTP-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css" media="screen">
body{ margin:0px; padding:0px;}
div{ width:400px; margin:0px auto;}
div h3{ background:#CCCCCC; font-size:14px; font-weight:bold; text-align:center; line-height:22px; margin:6px 0px; padding:0px;}
div textarea{ width:388px; height:120px; border:#999999 1px solid; margin:0px; padding:0px; font-size:12px; padding: 5px; line-height:16px;}
div p{ font-size:12px; margin:0px; line-height:22px;}
div p span{ color:#FF6600; font-weight:bold;}
</style>
<title>JAVAscript限制文字方塊輸入的最大字元數</title>
</head>

<body>
<div>
<h3>字元數測試</h3>
<textarea rows="20" cols="50" onkeyup=" checkMaxLength(this,20)" onpaste="return false;" ></textarea>
<p>最多<span>20</span>個字元，一個漢字2個字元，你還可以輸入<span>20</span> 字元</p>
</div>

<script type="text/javascript">
var s=document.getElementsByTagName("span")[1];
function checkMaxLength(area, maxLength) {
      var currentStr="";
   if(area.value.length==0){s.innerHTML=maxLength;}
      for(var i=0,len=area.value.length;i<len;i++) {
            currentStr+=area.value.charAt(i);
           if(getCharLength(currentStr)>maxLength){
                  area.value=area.value.substr(0,i);
                    return;
           }else{
              s.innerHTML=maxLength-getCharLength(currentStr);
     }
     }
}

function getCharLength(str){
     var charLen=0;
  for(var i=0,len=str.length;i <len;i++){
       if(str.charCodeAt(i)>255){
         charLen+=2;
    }else{
        charLen+=1;
    }  
  }
  return charLen;
}
</script>
</body>
</html>
 

本文章原先以中文撰寫並發佈於 aliyun.com，亦設英文版本，僅作資訊用途。本網站不對文章的準確性，完整性或可靠性或其任何翻譯作出任何明示或暗示的陳述或保證。如對該文章有任何疑慮或投訴，請傳送電郵至 info-contact@alibabacloud.com 並提供相關疑慮或投訴的詳細說明。職員會於 5 個工作天內與您聯絡，一經驗證之後，即會刪除該侵權內容。

相關關鍵詞：
javascript javascript javascript import javascript in javascript javascript call javascript file javascript interpreter in javascript javascript javascript editor load javascript from javascript javascript w3
相關文章
輸入框自動適應寬度
讓IE支援CSS3圓角的方法
css position用法與導致頁面變形js處理方法
CSS實現的透明效果
IE8中text-align:center偏左的解決辦法
DIV+CSS還能走多遠

聯繫我們

該頁面正文內容均來源於網絡整理，並不代表阿里雲官方的觀點，該頁面所提到的產品和服務也與阿里云無關，如果該頁面內容對您造成了困擾，歡迎寫郵件給我們，收到郵件我們將在5個工作日內處理。

如果您發現本社區中有涉嫌抄襲的內容，歡迎發送郵件至： info-contact@alibabacloud.com 進行舉報並提供相關證據，工作人員會在 5 個工作天內聯絡您，一經查實，本站將立刻刪除涉嫌侵權內容。

熱門文章

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

Get Started for Free

  • Sales Support

    1 on 1 presale consultation

    Chat Contact Sales

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

    Open a Ticket

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.

    Learn More