保持插入符号在输入中的位置的其他方法:

$(document).ready(function() {
  $('.numbersOnly').on('input', function() {
    var position = this.selectionStart - 1;

    fixed = this.value.replace(/[^0-9\.]/g, '');  //remove all but number and .
    if(fixed.charAt(0) === '.')                  //can't start with .
      fixed = fixed.slice(1);

    var pos = fixed.indexOf(".") + 1;
    if(pos >= 0)
      fixed = fixed.substr(0,pos) + fixed.slice(pos).replace('.', '');  //avoid more than one .

    if (this.value !== fixed) {
      this.value = fixed;
      this.selectionStart = position;
      this.selectionEnd = position;
    }
  });
});

优点:

用户可以使用方向键、退格键、删除键、… 当你想要粘贴数字的时候就可以了

Plunker:演示工作

你可以使用带有number()方法的Validation插件。

$("#myform").validate({
  rules: {
    field: {
      required: true,
      number: true
    }
  }
});

如果你使用的是HTML5，你就不需要花大力气去执行验证。只要用——

<input type="number" step="any" />

step属性允许小数点有效。

保持插入符号在输入中的位置的其他方法:

$(document).ready(function() {
  $('.numbersOnly').on('input', function() {
    var position = this.selectionStart - 1;

    fixed = this.value.replace(/[^0-9\.]/g, '');  //remove all but number and .
    if(fixed.charAt(0) === '.')                  //can't start with .
      fixed = fixed.slice(1);

    var pos = fixed.indexOf(".") + 1;
    if(pos >= 0)
      fixed = fixed.substr(0,pos) + fixed.slice(pos).replace('.', '');  //avoid more than one .

    if (this.value !== fixed) {
      this.value = fixed;
      this.selectionStart = position;
      this.selectionEnd = position;
    }
  });
});

优点:

用户可以使用方向键、退格键、删除键、… 当你想要粘贴数字的时候就可以了

Plunker:演示工作

jquery。数值插件有一些bug，我通知了作者。它允许在Safari和Opera中使用多个小数点，而在Opera中不能输入退格键、方向键或其他几个控制字符。我需要正整数输入，所以最后我自己写了。

$(".numeric").keypress(function(event) {
  // Backspace, tab, enter, end, home, left, right
  // We don't support the del key in Opera because del == . == 46.
  var controlKeys = [8, 9, 13, 35, 36, 37, 39];
  // IE doesn't support indexOf
  var isControlKey = controlKeys.join(",").match(new RegExp(event.which));
  // Some browsers just don't raise events for control keys. Easy.
  // e.g. Safari backspace.
  if (!event.which || // Control keys in most browsers. e.g. Firefox tab is 0
      (49 <= event.which && event.which <= 57) || // Always 1 through 9
      (48 == event.which && $(this).attr("value")) || // No 0 first digit
      isControlKey) { // Opera assigns values for control keys.
    return;
  } else {
    event.preventDefault();
  }
});

／* 这是我的跨浏览器版本 如何允许只有数字(0-9)在HTML输入框使用jQuery? * /

$("#inputPrice").keydown(function(e){
    var keyPressed;
    if (!e) var e = window.event;
    if (e.keyCode) keyPressed = e.keyCode;
    else if (e.which) keyPressed = e.which;
    var hasDecimalPoint = (($(this).val().split('.').length-1)>0);
    if ( keyPressed == 46 || keyPressed == 8 ||((keyPressed == 190||keyPressed == 110)&&(!hasDecimalPoint && !e.shiftKey)) || keyPressed == 9 || keyPressed == 27 || keyPressed == 13 ||
             // Allow: Ctrl+A
            (keyPressed == 65 && e.ctrlKey === true) ||
             // Allow: home, end, left, right
            (keyPressed >= 35 && keyPressed <= 39)) {
                 // let it happen, don't do anything
                 return;
        }
        else {
            // Ensure that it is a number and stop the keypress
            if (e.shiftKey || (keyPressed < 48 || keyPressed > 57) && (keyPressed < 96 || keyPressed > 105 )) {
                e.preventDefault();
            }
        }

  });