20

我读了很多教程，但我不知道该怎么做，这是输入

input(type="text",name="price",id="price"data-bind="text: price,valueUpdate:['afterkeydown','propertychange','input']")

这是我的视图模型

price: ko.computed(function()
{
    return parseFloat(this.replace(' ','').replace(/[^0-9\.]+/g,"")) || '';
},this)

但这会导致错误：这没有方法替换？？？如何将价格值传递给计算函数？

4

10 回答 10

46

最好创建自定义绑定http://knockoutjs.com/documentation/custom-bindings.html，它只接受允许的字符 [0-9,.] 作为数字表示。

把这条线放到你的视野中

<input id="text" type="text" data-bind="numeric, value: number">

将此行放入您的模型中（记住将数字绑定为可观察属性）

ko.bindingHandlers.numeric = {
    init: function (element, valueAccessor) {
        $(element).on("keydown", function (event) {
            // Allow: backspace, delete, tab, escape, and enter
            if (event.keyCode == 46 || event.keyCode == 8 || event.keyCode == 9 || event.keyCode == 27 || event.keyCode == 13 ||
                // Allow: Ctrl+A
                (event.keyCode == 65 && event.ctrlKey === true) ||
                // Allow: . ,
                (event.keyCode == 188 || event.keyCode == 190 || event.keyCode == 110) ||
                // Allow: home, end, left, right
                (event.keyCode >= 35 && event.keyCode <= 39)) {
                // let it happen, don't do anything
                return;
            }
            else {
                // Ensure that it is a number and stop the keypress
                if (event.shiftKey || (event.keyCode < 48 || event.keyCode > 57) && (event.keyCode < 96 || event.keyCode > 105)) {
                    event.preventDefault();
                }
            }
        });
    }
};
于 2013-06-12T07:46:13.870 回答
9

Knockout 对此有扩展器。检查来自 knockoutjs.com 的此内容，解释如何使用可观察扩展器强制输入为数字。我将文档中的代码粘贴到此处：

源代码：查看

<p><input data-bind="value: myNumberOne" /> (round to whole number)</p>
<p><input data-bind="value: myNumberTwo" /> (round to two decimals)</p>

源代码：查看模型

ko.extenders.numeric = function(target, precision) {
    //create a writable computed observable to intercept writes to our observable
    var result = ko.pureComputed({
        read: target,  //always return the original observables value
        write: function(newValue) {
            var current = target(),
                roundingMultiplier = Math.pow(10, precision),
                newValueAsNum = isNaN(newValue) ? 0 : parseFloat(+newValue),
                valueToWrite = Math.round(newValueAsNum * roundingMultiplier) / roundingMultiplier;

            //only write if it changed
            if (valueToWrite !== current) {
                target(valueToWrite);
            } else {
                //if the rounded value is the same, but a different value was written, force a notification for the current field
                if (newValue !== current) {
                    target.notifySubscribers(valueToWrite);
                }
            }
        }
    }).extend({ notify: 'always' });

    //initialize with current value to make sure it is rounded appropriately
    result(target());

    //return the new computed observable
    return result;
};

function AppViewModel(one, two) {
    this.myNumberOne = ko.observable(one).extend({ numeric: 0 });
    this.myNumberTwo = ko.observable(two).extend({ numeric: 2 });
}

ko.applyBindings(new AppViewModel(221.2234, 123.4525));
于 2015-05-21T10:46:52.157 回答
5

我有一个类似的问题。

我还需要只确保 inter 值，对于 IE9 及更高版本（所以 type=numberical 是不够的），而且由于我们有很多国际客户，我也不能依赖键码，所以以下是我最终的结果和：

//In my js class method (self is this as usual)
self.ensureNumberical = function (data, e) {
    var keyValue = e.key;
    if (keyValue.match(/[0-9]/g)) {
        return true;
    }
    return false;
}

//In my MVC View
data-bind="event: { keypress: ensureNumberical }"
于 2018-02-15T14:07:16.183 回答
2

另一种方法：我发现 Knockout 与jQuery-validate结合使用效果很好。您只需要确保在尝试使用数值之前验证表单。

假设您有一个表单 DOM 元素，您可以通过以下方式设置验证规则

$(".yourform").validate({
    rules: {
        year: {
            digits: true,
            minlength: 4,
            maxlength: 4
        }
    },
    messages: {
        year: "Please enter four digits (e.g. 2009).",
    }
});

在您的视图模型中，您像往常一样设置双向绑定，例如通过self.year = ko.observable(""). 现在请确保$(".yourform").valid()在进一步处理之前致电self.year()。就我而言，我正在做var year = parseInt(self.year(), 10). 在表单验证之后，这总是会产生有意义的结果。

于 2014-09-25T22:53:29.983 回答
2

最适合今天的场景 https://github.com/Knockout-Contrib/Knockout-Validation

运行下面的代码段。输入非数字或超过 255 的内容将导致显示消息。

function model() {
  var self = this;
  this.myObj = ko.observable().extend({ digit: true }).extend({ max: 255});
  }
  
  var mymodel = new model();

$(document).ready(function() {
  ko.validation.init();
  ko.applyBindings(mymodel);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout-validation/2.0.3/knockout.validation.min.js"></script>

enter a digit less than or equal to  255 <input type="text" data-bind="textInput: myObj">

<p>
  Enter something other than a digit or over 255 will cause an error.
</p>

礼貌：布莱恩·德林格：https ://stackoverflow.com/a/42940109/3868653

于 2018-05-10T10:38:09.020 回答
1 
 <input type="text" id="alpha-validation" data-bind="value: YourDataName, valueUpdate: 'afterkeydown' , event: { 'input': AlphaCheck}" style="text-transform:uppercase">

创建 AlphaCheck 函数并添加它。

    $('#alpha-validation').keyup(function () {
        if (this.value.match(/[^0-9 ]/g)) {
            this.value = this.value.replace(/[^0-9 ]/g, '');
        }
    });

这将有效！

于 2016-04-22T12:24:42.907 回答
1

我们可以限制用户输入的用户多于两位十进制数 Ex. 23.81, 3452.83 修改代码如下。参考代码取自@Martin Surynek 的答案。

HTML -

<p>
    <input data-bind="value: myNumberOne" /> (round to whole number)</p>
  <p>
    <input data-bind="num, value: myNumberTwo" /> (round to two decimals)</p>

脚本 -

<script>
    ko.bindingHandlers.num = {
      init: function (element, valueAccessor) {
        $(element).on("keypress", function (event) {
          //debugger
          console.log(event.keyCode);
          var $this = $(this);
          var text = $this.val();

          // Stop insert two dots
          if ($this.val().indexOf('.') != -1 && (event.which == 190 || event.which == 110)) {
            event.preventDefault();
          }

          // Allow: backspace, delete, tab, escape, and enter
          if (event.keyCode == 46 || event.keyCode == 8 || event.keyCode == 9 || event.keyCode == 27 || event.keyCode ==
            13 ||
            // Allow: Ctrl+A
            (event.keyCode == 65 && event.ctrlKey === true) ||
            // Allow: .   ,event.keyCode == 188 ||
            ( event.keyCode == 190 || event.keyCode == 110) ||
            // Allow: home, end, left, right
            (event.keyCode >= 35 && event.keyCode <= 39)) {
            // let it happen, don't do anything
            return;
          }

          // Ensure that it is a number and stop the keypress
          if (event.shiftKey || (event.keyCode < 48 || event.keyCode > 57) && (event.keyCode < 96 || event.keyCode >
              105)) {
            event.preventDefault();
          }

          if ((event.which == 46) && (text.indexOf('.') == -1)) {
            setTimeout(function () {
              if ($this.val().substring($this.val().indexOf('.')).length > 3) {
                $this.val($this.val().substring(0, $this.val().indexOf('.') + 3));
              }
            }, 1);
          }

          if ((text.indexOf('.') != -1) &&
            (text.substring(text.indexOf('.')).length > 2) &&
            (event.which != 0 && event.which != 8) &&
            ($(this)[0].selectionStart >= text.length - 2)) {
            event.preventDefault();
          }          
          //console.log($(this)[0].selectionStart >= text.length - 2);
        });
      }
    };


    ko.extenders.numeric = function (target, precision) {
      //create a writable computed observable to intercept writes to our observable

      var result = ko.pureComputed({
        read: target, //always return the original observables value
        write: function (newValue) {

          var current = target(),
            roundingMultiplier = Math.pow(10, precision),
            newValueAsNum = isNaN(newValue) ? 0 : parseFloat(+newValue),
            valueToWrite = Math.round(newValueAsNum * roundingMultiplier) / roundingMultiplier;

          //only write if it changed
          if (valueToWrite !== current) {
            target(valueToWrite);
          } else {
            //if the rounded value is the same, but a different value was written, force a notification for the current field
            if (newValue !== current) {
              target.notifySubscribers(valueToWrite);
            }
          }
        }
      }).extend({
        notify: 'always'
      });

      //initialize with current value to make sure it is rounded appropriately
      result(target());

      //return the new computed observable
      return result;
    };

    function AppViewModel(one, two) {
      this.myNumberOne = ko.observable(one).extend({
        numeric: 0
      });
      this.myNumberTwo = ko.observable(two).extend({
        numeric: 2
      });
    }

    ko.applyBindings(new AppViewModel(221.2234, 123.4525));
  </script>
于 2018-01-16T06:22:28.913 回答
0

我知道这个问题已经有一年了，但为了页面的功能访问者，让我发布这个问题。

看一下这个：

ko.bindingHandlers.numericnumbers = {
init: function (element) {
    $(element).on('keypress', function (number) {
        number = (number) ? number : window.event;
        var charcode = (number.which) ? number.which : number.keyCode;
        if (charcode > 31 && (charcode < 48 || charcode > 75))
            number.preventDefault();
    });
}};
于 2017-01-08T08:29:28.473 回答
0

创建指向闪亮的新代码的数据绑定：

<input id="price" name="price" type="text" data-bind="numeric">

闪亮的新淘汰赛代码：

price = ko.observable();
price.subscribe(function(newValue) {
    price = newValue.replace(/[\D\.]/g, '');
});

这意味着每次更新价格时，它都会应用函数中的逻辑（在这种情况下，去掉任何不是数字或句点的东西），并将其直接应用于价格。您还可以在此处添加其他验证或很酷的功能，例如在开头添加货币 sybmol，将其保留为小数点后 2 位等...

于 2017-06-16T03:56:39.567 回答
0

在“keydown”事件的帮助下，我们可以限制文本框中应该包含数值的其他键。

$(document).ready(function(){                
        $("selector").on("keydown", function (e) {
            //numbers, delete, backspace, arrows
            var validKeyCodes = [8, 9, 37, 38, 39, 40, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57];
            if (!($.inArray(e.keyCode, validKeyCodes) >= 0))
                    e.preventDefault();                 
        });           
    });
于 2017-07-03T04:14:34.083 回答