使用knockout JS从select标签中删除optionsCaption

Question

如何删除optionsCaption从select tag ?使用knockout JS

我的意思select tag是:

<select data-bind="options: categories, optionsText: 'type', optionsCaption: 'Select Any Ticket type', value: chosenCategory, disable: showReservationDetails, event: {change: calRemainingTickets}"></select>

它Select Any Ticket首先显示option.on change的select tag我想删除Select Ant Ticket option.

我们怎么能从remove中required option得到select tag ?

先感谢您 .

Answer 1

您可以将optionsCaption绑定到observable,并将observable的值设置为undefined.我修改了Joe的代码来做到这一点.

var vm = function () {
    this.optionsCaption = ko.observable('Select any');
    this.categories = ko.observableArray([ {type: 'Type 1' }, { type: 'Type 2' }]);
    this.chosenCategory = ko.observable('Select Any Ticket type');
    this.showReservationDetails = ko.observable(false);
    this.calRemainingTickets = function () {
        this.optionsCaption(undefined);
    }.bind(this);
}

ko.applyBindings(new vm());

<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.0.0/knockout-min.js"></script>
<select data-bind="options: categories, optionsCaption: optionsCaption, optionsText: 'type', value: chosenCategory, disable: showReservationDetails, event: {change: calRemainingTickets}"></select>