Question

如何在金额输入字段中进行验证？

在文本框中仅允许减号（负号）一次。例如，-10.00。不允许使用其他特殊字符，因为这是金额字段。
它不应包含字母。仅允许数字。
十进制（。）在文本框中只能出现一次。

Answer 1

已编辑：我想这就是您想要的。在jsfiddle.net中找到了这个。无需插件。

HTML：

<input type="text" maxlength="10" id="myInput">

JavaScript

var input = document.getElementById("myInput");

input.onkeypress = function(e) {    e = e || window.event;
var charCode = (typeof e.which == "number") ? e.which : e.keyCode;

// Allow non-printable keys
if (!charCode || charCode == 8 /* Backspace */ ) {
    return;
}

var typedChar = String.fromCharCode(charCode);

// Allow numeric characters
if (/\d/.test(typedChar)) {
    return;
}

// Allow the minus sign (-) if the user enters it first
if (typedChar == "-" && this.value == "") {
    return;
}

// In all other cases, suppress the event
return false;

};

Answer 2

我刚刚根据您的情况写了这个，请在下面进行测试：

更新：修改为可同时在jquery和javascript inline中使用

// This is a middleware that takes as parameter "decimals" which is by default 2

currencyNumber = function(decimals) {

  if (typeof decimals !== 'number') {
    decimals = 2;
  }

  return function(e) {

    var input = $(this instanceof Window ? e : e.currentTarget);

    var value = $.trim(input.val());

    var hasNegativeNumber = value.substr(0, 1) === '-' ? '-' : '';

    var nextValue = value
      .replace(/\.+/g, '.')
      .replace(/[^0-9\.]+/g, '');

    if (nextValue === '.' || (nextValue.length > 1 && nextValue === "00")) {
      nextValue = '';
    }

    var dotsFound = nextValue.split('.').filter(function(i) {
      return i.length;
    });
    var afterDot = '';
    var beforeDot = '';

    if (dotsFound.length > 1) {

      beforeDot = dotsFound[0];

      dotsFound.splice(0, 1);

      afterDot = dotsFound.join('');

      nextValue = +(beforeDot) + '.' + afterDot.substr(0, decimals);

    }

    if (nextValue.substr(nextValue.length - 1, 1) === '.') {

      input.one('change', function() {

        if (nextValue.substr(nextValue.length - 1, 1) === '.') {
          nextValue = nextValue.substr(0, nextValue.length - 1);

          input.val(hasNegativeNumber + nextValue);

        }

        $(this).off('change');

      })

    } else {

      input.off('change')

    }

    input.val(hasNegativeNumber + nextValue);

  };


}

// Here is where you call the middleware

$("#amount").on("keyup", currencyNumber(3));

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="banner-message">
  Test your number (bind is from jquery):
  <input id="amount" type='text' />
  <br /> Test your number (bind is from javascript inline):
  <input id="amount-inline" onkeyup="currencyNumber(3)(this);" type='text' />

</div>

如何使用Jquery验证输入文本框中的允许减号（-）和仅数字？

2 个答案: