Question

是否可以使用knockout js对此场景进行建模？

说我有3个字段：

Current Income：如果我更改此值，则Retirement Income需要更新为(Current Income * Percentage of Current Income) / 100

Retirement Income：如果我更改此值，则Percentage of Current Income需要更新为(Retirement Income/Current Income) * 100

Percentage of Current Income：如果我更改此值，则Retirement Income需要更新为(Current Income * Percentage Of Current Income) / 100

这是某种循环依赖吗？可以使用knockout js建模吗？我假设所有字段都需要计算...但我不确定如何设置默认值或使用尚未声明的计算的observable。

jsfiddle起点：http://jsfiddle.net/LkqTU/4482/

Answer 1

您可以使用read/write computed：

var ViewModel = function() {
    var self = this;

    self.currentIncome = ko.observable(1000);
    self.currentIncomePercent = ko.observable(5);

    self.retirementIncome = ko.computed({
        read: function() {
            var result = self.currentIncome() * self.currentIncomePercent() / 100;
            return result.toFixed(2);
        },
        write: function(value) {
            var result = value / self.currentIncome() * 100;
            self.currentIncomePercent(result.toFixed(2));
        }
    });
};

ko.applyBindings(new ViewModel());

这是工作小提琴：http://jsfiddle.net/vyshniakov/LkqTU/4503/

Knockout js可以很容易地建模

1 个答案: