当子属性更改时，如何触发NgComponent的更新 [英] How to trigger an update of NgComponent when child property changes

问题描述

我是一个完整的初学者AngularDart（和Dart）;我按照教程，但这是我似乎找不到一个答案。

I am a complete beginner to AngularDart (and Dart); I followed the tutorials but this is something I can't seem to find a answer to.

我有两个NgComponents工作完美：

I have two NgComponents that work perfectly:

 <colorImage car-color="ctrl.car.color"></colorImage>
 <carImage car="ctrl.car"></carImage>

我的控制器ctrl有一个名为car的属性，car颜色。
当car.color更改时，colorButton NgComponent更新，但是carImage NgComponent不更新。

My controller "ctrl" has a property named "car" and "car" has a property named "color". When "car.color" changes, the colorButton NgComponent updates, but the carImage NgComponent does not.

如果car.color .color更改？

How can I trigger an update of carImage when "car.color" changes?

谢谢！

推荐答案

在您的CarImage中设置一个手表到 car.color 。
这看起来取决于你用于汽车的数据结构。

You have to set a watch to car.color inside your CarImage. How this looks depends on what data structure you use for car.

// constructor
CarImage(Scope scope) {
   scope.$watch(() => car.color, (color) => doSomething(color));
}

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