在承诺中设置状态时遇到问题

Question

我的componentDidMount()函数中有一系列 promise。 在values.then(function(result)承诺中，我正在尝试设置状态。我收到此错误Unhandled Rejection (TypeError): Cannot read property 'setState' of undefined but researched this error and I need to bind my promise using一个箭头函数，让它可以访问this关键字。

componentDidMount() {
        let general = {};
        let values = [];
        //gets selected setting form schema
        getSettingsForms().then((response) => {
            this.setState({settingsForms: response});
            general = response[this.state.selectedSetting];
        }).then(response => {
            values = getSettingsConfig(this.state.selectedSetting, general);
            values.then(function(result) {
                this.setState({
                    formSchema: result[1],
                    selectedSetting: this.state.selectedSetting,
                    settings: result[0]

                })

            })
        })
    }

问题是我不知道将箭头函数放在这种承诺上的位置。 无论我把它放在哪里，我都会收到一条错误消息，说是Unexpected token, expected "{" ，然后当我尝试放入大括号时，我又收到了另一个错误。

componentDidMount() {
        let general = {};
        let values = [];
        //gets selected setting form schema
        getSettingsForms().then((response) => {
            this.setState({settingsForms: response});
            general = response[this.state.selectedSetting];
        }).then(response => {
            values = getSettingsConfig(this.state.selectedSetting, general);
            values.then(function(result) => {
                this.setState({
                    formSchema: result[1],
                    selectedSetting: this.state.selectedSetting,
                    settings: result[0]

                })

            })
        })
    }

将此箭头函数放入values.then(function(result)承诺以便我可以设置状态的正确方法是什么？`

Answer 1

就像您使用的其他两个箭头函数一样：

componentDidMount() {
        let general = {};
        let values = [];
        //gets selected setting form schema
        getSettingsForms().then((response) => {
            this.setState({settingsForms: response});
            general = response[this.state.selectedSetting];
        }).then(response => {
            values = getSettingsConfig(this.state.selectedSetting, general);
            values.then(result => {
                this.setState({
                    formSchema: result[1],
                    selectedSetting: this.state.selectedSetting,
                    settings: result[0]

                })

            })
        })
    }