[英]Javascript, ReactJs setState not working
我正在学习反应,并且已经在本教程中进行在线问答,所以我尝试进行一些调整,我希望用户单击HellYa,它将使答案类型增加-例如,“ Brown”,“ D”,“ JP”分别增加+1 ,这是我的quizQuestion.js
{
question: "I am task oriented in order to achieve certain goals",
answers: [
{
type: "Brown,D,JP",
content: "Hell Ya!"
},
{
type: " ",
content: "Nah"
}
]
},
我的初始化状态构造函数如下
this.state = {
counter: 0,
questionId: 1,
question: '',
answerOptions: [],
answer: '',
answersCount: {
Green: 0,
Brown: 0,
Blue: 0,
Red: 0,
A: 0,
B: 0,
C: 0,
D: 0,
EI: 0,
SN: 0,
TF: 0,
JP: 0
},
result: ''
};
在本教程之后,我正在使用react-addons-update来更新answerCount和answer,这是我的功能
setUserAnswer(answer) {
if (answer.trim()) {
const answer_array = answer.split(',');
let updatedAnswersCount = null;
answer_array.forEach((answer) => {
updatedAnswersCount = update(this.state.answersCount, {
[answer]: {$apply: (currentValue) => currentValue + 1}
});
}, this);
this.setState({
answersCount: updatedAnswersCount,
answer: answer
});
}
}
但是经过几次尝试,我仍然不知道如何将答案类型分别递增1,例如,现在它仅更新JP +1,但不更新Brown和D,我该怎么办? 谢谢
似乎总是使用当前状态作为基础对象,因此只会更新foreach中的最后一个答案。
请尝试以下操作:
setUserAnswer(answer) {
if (answer.trim()) {
const answer_array = answer.split(',');
let answerCountUpdates = update(this.state.answersCount, {$merge: {}}) // copy this.state.answersCount, will search a better way
answer_array.forEach((answer) => {
answerCountUpdates = update(answerCountUpdates, {
[answer]: {$apply: (currentValue) => currentValue + 1}
});
}, this);
updatedAnswersCount = update(this.state.answersCount, {$merge: answerCountUpdates})
this.setState({
answersCount: updatedAnswersCount,
answer: answer
});
}
}
看来您已经将forEach()
的迭代对象命名为“ answer”,以及传递给setUserAnswer()
的参数。 尝试更改其中之一,因为这可能会引起问题。
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