我怎样才能让有条件的knockout.js约束力？ [英] How can I make conditional binding in knockout.js?

问题描述

我想这一个：

<div data-bind="attr: {class: itemSelected? 'selected' : 'unselected' }"></div>

但它不工作:)

But it does not work :)

推荐答案

假设你有这样的：

function viewModel() {
    this.itemSelected = ko.observable(true);
}
ko.applyBindings(new viewModel());​

添加（）后itemSelected拿到观察到的当前值，您可以用三元运算符是：

Add a () after itemSelected to get the current value of the observable that you can use with the ternary operator:

＆LT; D​​IV数据绑定=ATTR：{：'选择'itemSelected（）：上课吗？未选中的'}＆GT;＆LT; / DIV＆GT;

http://jsfiddle.net/RK7Ty/

如果您并不需要指定用于非选定状态未被选中的类，你可以这样做，而不是：

If you didn't need to assign the unselected class for the non selected state you could do this instead:

<div data-bind="css: { selected: itemSelected }"></div>​

http://jsfiddle.net/RK7Ty/1/

这篇关于我怎样才能让有条件的knockout.js约束力？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！