检查多行文本框大小 [英] Check size of multi-line textbox

问题描述

我一直在尝试了几个小时摸不着头脑。
为什么要在一个多行文本框的ASP控制，我有140个字符的限制，但有时我可以输入141或142个字符，特别是使用回车键？

下面是我的code

 函数CheckSize（0，大小）{
    如果（O！= NULL）{
        变种S = o.value.length;
        如果（S＆GT;大小）{
            调试器;
            警报（'。Lamentamos MAS FOI atingidoØLIMITE段的MáximoØtexto一个introduzir \\ nSugerimos阙introduza嗯texto COM menos德'+规模+'CARACTERES \\ nAgradecemos一个SUA COM $ P $这Pensão。'）;
            //警报（resources.error_reachedMaxNumberOfChars.replace（{0}，字符串（大小）））;
            变种修剪= o.value.trim（）;
            o.value = trim.substring（0，大小 -  1）;
        }
    }
}
 

解决方案

我的猜测是，是，你正在运行到相当普遍的最大长度的错误，已经$ P在众多现代浏览器$ psent（<一个href=\"https://www.google.se/search?q=textarea%20maxlength%20bug&oq=textarea%20max&aqs=chrome.0.59l2j0j57j62l2.6501j0&sourceid=chrome&ie=UTF-8\"相对=nofollow>做一个谷歌搜索一下）。这是你如何可以解决此问题的一个例子，虽然未硬化的每一种情况（即粘贴）。

CSS

  .hidden {
    visibility：hidden的;
}
 

HTML

 ＆LT; textarea的ID =myTextboxMAXLENGTH =140行=4COLS =35＆GT;＆LT; / textarea的＆GT;
＆LT; D​​IV ID =计数＆GT; 0℃; / DIV＆GT;
＆LT; D​​IV ID =警戒级=隐藏＆gt;对于最多字符＆LT;！/ DIV＆GT;
＆LT; D​​IV ID =换行级=隐藏＆GT;新行prevented，因为它是2个字符＆LT;！/ DIV＆GT;
 

的JavaScript

  VAR myTextBox =的document.getElementById（'myTextbox'），
    数=的document.getElementById（计数），
    警报=的document.getElementById（'警报'），
    换行符=的document.getElementById（'新行'），
    最大长度= 140;myTextBox.addEventListener（输入，功能（E）{
    VAR值= e.target.value.replace（/ \\ r吗？\\ n /克，'\\ r \\ n），
        长度= value.length;
    如果（长度GT; =最大长度）{
        如果（长度GT;最大长度）{
            长度=最大长度 -  1;
            e.target.value = value.slice（0，长度）;
            newline.classList.remove（'隐藏'）;
        }其他{
            alert.classList.remove（'隐藏'）;
            newline.classList.add（'隐藏'）;
        }
    }其他{
        alert.classList.add（'隐藏'）;
        newline.classList.add（'隐藏'）;
    }    count.textContent =长度;
}，FALSE）;
 

在的jsfiddle

I've been trying for hours to figure this out. Why in a multi-line textbox asp control, I have a limit of 140 characters but sometimes I can input 141 or 142 characters, especially with the use of the enter key?

Here's my code

function CheckSize(o, size) {
    if (o != null) {
        var s = o.value.length;
        if (s > size) {
            debugger;
            alert('Lamentamos mas foi atingido o limite máximo para o texto a introduzir.\nSugerimos que introduza um texto com menos de ' + size + ' caracteres.\nAgradecemos a sua compreensão.');
            // alert(resources.error_reachedMaxNumberOfChars.replace("{0}",String(size)));
            var trim = o.value.trim();
            o.value = trim.substring(0, size - 1);
        }
    }
}

解决方案

My guess is, is that you are running into the fairly common maxLength bug that has been present in a number of modern browsers (do a Google search about it).This is an example of how you could work around the problem, though not hardened for every situation (i.e. paste).

CSS

.hidden {
    visibility: hidden;
}

HTML

<textarea id="myTextbox" maxlength="140" rows="4" cols="35"></textarea>
<div id="count">0</div>
<div id="alert" class="hidden">At max chars!</div>
<div id="newline" class="hidden">Newline prevented as it is 2 characters!</div>

Javascript

var myTextBox = document.getElementById('myTextbox'),
    count = document.getElementById('count'),
    alert = document.getElementById('alert'),
    newline = document.getElementById('newline'),
    maxLength = 140;

myTextBox.addEventListener('input', function (e) {
    var value = e.target.value.replace(/\r?\n/g, '\r\n'),
        length = value.length;


    if (length >= maxLength) {
        if (length > maxLength) {
            length = maxLength - 1;
            e.target.value = value.slice(0, length);
            newline.classList.remove('hidden');
        } else {
            alert.classList.remove('hidden');
            newline.classList.add('hidden');
        }
    } else {
        alert.classList.add('hidden');
        newline.classList.add('hidden');
    }

    count.textContent = length;
}, false);

On jsFiddle

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