Question

我在看make an input only-numeric type on knockout。接受的答案工作正常，但如何防止输入多个小数点（如4.4.4）（或如何防止第二个小数点？）

代码是这样的：

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

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();
            }
        }
    });
}
};

Answer 1

自定义绑定对我来说不太好看。我建议只使用Knockout Validation，这在我的工作流程中被证明是一个很棒的插件。语法很简单：ko.observable(...).extend({ number: true })。您还可以添加最小/最大验证：.extend({ number: true, min: 0, max: 100 }) // percentage，插件允许将css类添加到无效元素。

见下面的例子。它完全符合您的要求。

＆＃13;

function viewModel() {
  this.number = ko.observable(0).extend({ number: true });
}

ko.applyBindings(new viewModel(), document.body);

＆＃13;

<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-min.js"></script>
<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-validation/2.0.3/knockout.validation.js"></script>

<input data-bind="textinput: number" />

＆＃13;

Javascript：数字输入 - 防止多个小数点

1 个答案: