Jquery help to enforce maxlength on textarea?

问题

Here is Jquery to enforce maxlength for textarea when you add the attribute "maxlength". Maxlength is not supported with IE. How do I adjust my code to handle multiple textarea(s) on the page? Currently if I add text to any textarea, they all countdown with the same value.

Jquery:

$(document).ready( function () {

maxLength = $("textarea").attr("maxlength");
    $("textarea").after("<div><span id='remainingLengthTempId'>" 
              + maxLength + "</span> remaining</div>");

    $("textarea").bind("keyup change", function(){checkMaxLength(this.id,  maxLength); } )

});

function checkMaxLength(textareaID, maxLength){

    currentLengthInTextarea = $("#"+textareaID).val().length;
    $(remainingLengthTempId).text(parseInt(maxLength) - parseInt(currentLengthInTextarea));

    if (currentLengthInTextarea > (maxLength)) { 

        // Trim the field current length over the maxlength.
        $("textarea").val($("textarea").val().slice(0, maxLength));
        $(remainingLengthTempId).text(0);

    }
}

Html:

Skills:
<textarea id="1" maxlength="200" rows="10" cols="60" ></textarea>

Postions:
<textarea id="2" maxlength="200" rows="10" cols="60" ></textarea>

Comments
<textarea id="3" maxlength="100" rows="10" cols="60" ></textarea>

回答1:

This is the best solution! Put this into your script tag in HTML code

$("textarea[maxlength]").on("propertychange input", function() {
    if (this.value.length > this.maxlength) {
        this.value = this.value.substring(0, this.maxlength);
    }  
});

and now use <textarea maxlength="{your limit}"></textarea> for {your limit} chars limit.

回答2:

The solution is here:

http://web.enavu.com/daily-tip/maxlength-for-textarea-with-jquery/

$(document).ready(function() {

    $('textarea[maxlength]').keyup(function(){
        //get the limit from maxlength attribute
        var limit = parseInt($(this).attr('maxlength'));
        //get the current text inside the textarea
        var text = $(this).val();
        //count the number of characters in the text
        var chars = text.length;

        //check if there are more characters then allowed
        if(chars > limit){
            //and if there are use substr to get the text before the limit
            var new_text = text.substr(0, limit);

            //and change the current text with the new text
            $(this).val(new_text);
        }
    });

});

回答3:

Cant you use this :

    class="validate[required,maxSize[50]] "

回答4:

This solution is working as native HTML text-area , MAX-Length property

Var MaxLength=100; 
$('#Selector').keydown(function (e) {
            var text = $(this).val();
            var chars = text.length;
            if (chars > MaxLength) {
                if (e.keyCode == 46 || e.keyCode == 8 || e.keyCode == 37 || e.keyCode == 38 || e.keyCode == 39 || e.keyCode == 40) {
                    return true;
                }
                return false;
            }
            return true;
        });

Don't set the Maxlength property in the server side control (asp:TextBox) as server won't convert maxLength property to HTML markup when returning to your browser.

来源：https://stackoverflow.com/questions/15031513/jquery-help-to-enforce-maxlength-on-textarea

标签

jquery

validation

textarea