如何在React同步过程中进行setState

Question

在我的应用程序中，我需要将异步转换为同步（即）一旦 setState 设置了值，那么我需要在调用后从 api 获取数据

logChange(val) {
    this.setState({
        fetchIntentReport: {
            startDate: this.state.fetchIntentReport.startDate,
            endDate: this.state.fetchIntentReport.endDate,
            intents: val.split(','),
        },
    });
    this.props.fetchIntentReports({
        startDate: this.state.fetchIntentReport.startDate,
        endDate: this.state.fetchIntentReport.endDate,
        intents: this.state.fetchIntentReport.intents,
    });
}

一旦值设置为意图，那么我需要通过 redux 调用 fetchIntentReports api 调用。

Answer 1

我强烈建议不要强制同步调用。幸运的是，setState允许回调函数，因此您可以执行以下操作：

logChange(val) {
    var startDate = this.state.fetchIntentReport.startDate;
    var endDate = this.state.fetchIntentReport.endDate;
    var intents = val.split(',');

    this.setState({
        fetchIntentReport: {
            startDate,
            endDate,
            intents
        }
    }, () => {
        // if you need the updated state value, use this.state in this callback
        // note: make sure you use arrow function to maintain "this" context
        this.props.fetchIntentReports({
            startDate,
            endDate,
            intents
        })
   );
}