textarea通過javascript驗證

Question

有2種單選按鈕。

如果檢查短信按鈕，然後文本區域的最大長度設置90個字節

如果檢查LMS按鈕，然後testarea的最大長度設置2000個字節

，我們可以檢查我有多少把文本的文本區域在「totalWordLimit」

，但有問題

如果我把許多文本通過複製粘貼&，文本區域成爲殘疾人

以及當我更改單選按鈕時，計數編號不會初始化。

我需要在這段代碼中修復什麼？

<script type="text/javascript"> 
 

 
var setTotalNumberOfWordCounter = "90"; 
 

 
function displayWordCounter(){ 
 
var getTextValue = document.smsForm.msg.value; // Get input textarea value 
 
var getTextLength = getTextValue.length; // Get length of input textarea value 
 
var one_char = ""; 
 
var rbyte = 0; 
 
var rlen = 0; 
 
for(var i=0; i<getTextLength; i++){ 
 
\t one_char = getTextValue.charAt(i); 
 
\t if(escape(one_char).length > 4){ 
 
\t  rbyte += 2;        // special language(2Bytes) 
 
\t }else{ 
 
\t  rbyte++;        // 1Byte 
 
\t } 
 

 
\t if(rbyte <= setTotalNumberOfWordCounter){ 
 
\t  rlen = i+1;        //return text count 
 
\t } 
 
} 
 
if(rbyte > setTotalNumberOfWordCounter){  //compare this length with total count 
 
     getTextValue = getTextValue.substring(0,setTotalNumberOfWordCounter); 
 
     document.smsForm.msg.value =getTextValue; 
 
     return false; 
 
} 
 
\t document.smsForm.totalWordLimit.value = (setTotalNumberOfWordCounter-rbyte); 
 
\t var tt = document.getElementById("Textarea"); 
 
\t 
 
\t if(document.smsForm.totalWordLimit.value === "0"){ \t \t \t 
 
\t \t tt.value = tt.value.substring(0, tt.value.length-1); 
 
\t } 
 
} 
 

 
</script> 
 

 
<script type="text/javascript"> 
 
    function ShowHide() {   
 
     var Textarea = document.getElementById("Textarea");   
 
     if(document.getElementById('sms').checked) { 
 
     \t setTotalNumberOfWordCounter = "90"; 
 
     }else if(document.getElementById('lms').checked) { 
 
    \t \t setTotalNumberOfWordCounter = "2000"; 
 
     } 
 
      
 
    }  
 
    
 
</script>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script> 
 
<input type="radio" name="sms" id="sms" onclick="ShowHide()" value="ss" checked>SMS 
 
<input type="radio" name="lms" id="lms" onclick="ShowHide()" value="ll"> LMS 
 
<textarea name="msg" class="main_txt_area" id="Textarea" onkeydown="return displayWordCounter();" cols="40" rows="10" ></textarea> 
 
\t \t \t \t \t \t \t \t \t 
 
<script type="text/javascript"> 
 
\t \t \t \t document.write("<div class='total_count'>total remaining Charatctor: <input type='text' class='show_count' name='totalWordLimit' size=4 readonly value="+setTotalNumberOfWordCounter+"></div>"); 
 
</script>

Answer 1

試試這個

function ShowHide() {   
    var Textarea = document.getElementById("Textarea");   
    if(document.getElementById('sms').checked) { 
     Textarea.setAttribute("maxlength", "90"); 
    }else if(document.getElementById('lms').checked) { 
     Textarea.setAttribute("maxlength", "2000"); 
    } 

} 

，並嘗試onpaste功能textarea元素

<textarea name="msg" class="main_txt_area" id="Textarea" onkeydown="return displayWordCounter();" cols="40" rows="10" onpaste="return displayWordCounter();"></textarea>