多个文本域字数限制

Posted 2020-06-14

<script>
function getStringUTFLength(str) {
 var value = str.replace(/[\u4e00-\u9fa5]/g," ");
 //将汉字替换为两个空格
 return value.length;
}
function leftUTFString(str,len) {
 if(getStringUTFLength(str)<=len) {
  return str;
 }
 var value = str.substring(0,len);
 while(getStringUTFLength(value)>len) {
  value = value.substring(0,value.length-1);
 }
 return value;
}
function count(id) {
 var len=300;
 var value = $(‘textarea[resultid=‘+id+‘]‘).val();
 if(getStringUTFLength(value)>=len) {
  $(‘textarea[resultid=‘+id+‘]‘).val(leftUTFString(value,len));
 }
 $(‘input[resultid=‘+id+‘]‘).val(len-getStringUTFLength(value));
}
</script>

 

 <div class="content"><b><td>五、简答题</td></b></div><br><br>
          <c:forEach var="question" items="${testPaper.questions}">
          <c:if test="${‘5‘ eq question.status }">
          <div class="content">
          <span style="color: #22536A;font-weight: bold;font-size: 16px;"> <%=i++ %>、<c:out value="${question.questionName }"/></span>
          <ul style="list-style: none;margin-left: 0px">
                         剩余可输入字数：<font color="red"><input resultid="${question.id }"  readonly type="text" size="3" id="result" value="300"></font>
          <li><textarea  id="${question.id }" resultid="${question.id }"  name="qId<c:out value="${question.id }"/>"  rows="10" cols="80" onkeypress="count(${question.id })" onkeyup="count(${question.id })" onblur="count(${question.id });" onChange="count(${question.id });"></textarea></li>
          </ul>
          </div>
          </c:if>
      </c:forEach>