敲除计算的可观察写入不更新

Question

以下是计算的可观察对象，我调用了它的写入函数，但写入不会更新计算的值。

self.pagesToBeDisplayed = ko.computed({
    read: function () {
       return self.pages();
    }, write: function (totalCount) {
        self.pages(totalCount) 
    },
    deferEvaluation: true
});

我将上面的可观察对象称为 self.pagesToBeDisplayed(5)。但是，只有 self.pages 的值被更新并且 self.pagesToBeDisplayed 仍然是旧值。

Answer 1

它按预期工作：

var viewmodel = function(){
  var self = this;
  self.pages = ko.observable(2);
  self.pagesToBeDisplayed = ko.computed({
    read: function () {
       return self.pages();
    }, write: function (totalCount) {
        self.pages(totalCount) 
    },
    deferEvaluation: true
  });
  
  self.update = function(){
    self.pagesToBeDisplayed(5);
  };
};

ko.applyBindings(new viewmodel());

<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-min.js"></script>

Update via input:
<input type="number" data-bind="value: pagesToBeDisplayed">
<br>

Update via JS:
<button data-bind="click: update">Update</button>

<br><br>
Latest values:
<br>
self.pages:<span data-bind="text: pages"></span>
<br>
self.pagesToBeDisplayed:<span data-bind="text: pagesToBeDisplayed"></span>

可能是您代码的其他部分导致了问题。

敲除计算的可观察写入不更新

Knoockout computed observable write doesnt update

javascript

knockout.js

computed-observable