当状态改变时，Reach 子项不会更新 [英] Reach child does not update when state changes

问题描述

我创建了一个代码片段来演示这个问题:

I have created a code snippet to demonstrate the issue:

https://codesandbox.io/s/o1v4qxw3yy

本质上，当单击复选框时，checkedValues(一个 id 数组)不会传递给 ChildComponent.除非我同时发送另一个变量.如果在 ParentComponent 中取消注释 cat 行 @32，它就会开始工作.

Essentially the checkedValues (an array of ids) does not get passed to the ChildComponent when a checkbox is clicked. Unless I send another variable along with it. If you uncomment the cat line @32 in the ParentComponent, it all starts working.

我注意到 ChildComponent 周围的 Apollo HOC 接收到新值 live，但是 ChildComponent 不会更新，除非进行另一个状态更改.

I have noticed that the Apollo HOC around the ChildComponent receives the new value live, but the ChildComponent does not update unless another state change is made.

我不确定我做错了什么.

I am not sure what I am doing wrong.

推荐答案

您正在改变状态.你应该保持状态不变.创建一个新数组，然后对该数组进行更改.所以转换

You are mutating the state. You should keep the state immutate. Create a new array and then make the changes to that array. So convert

let newArray = this.state.checkedValues;

到

let newArray = [...this.state.checkedValues]; 

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