Javascript 我怎样才能得到调度的答复？

我有一个组件，它有一个表单，此时在提交按钮上执行clic，我调用一个函数handleSubmit它在我的组件上，这个函数调用一个动作，通过分派和这个动作，我调用一个服务HTTP请求

手推

actions.addDevice

服务添加设备

---

我希望组件中的响应能够进行验证，但由于请求是异步的，我永远无法获得响应，只能打印未定义的变量。如何获得同步响应？或者我需要做什么才能进行验证？

您没有返回promise service.addDevice

所以你可以做退货服务。添加设备。。。在handleSubmit中，您执行分派…然后data=>…对数据执行某些操作

这是异步的。因此，从console.log返回undefined并不奇怪。即使在分派过程完成之前也要执行console.log。使用承诺或异步等待语法。我建议使用异步等待语法

handleSubmit = (e) => {
   e.preventDefault()
   const { validateFields } = this.props.form;

   validateFields(async (err, params) => {
       if (!err) {
            const { user, dispatch } = this.props;

            let response =await dispatch(actions.addDevice(params))
            console.log(response); //Response is undefined
       }
    });
}

---

请用此代码替换您的代码

手推

actions.addDevice

---

要在组件中使用响应，您还需要做3件事：根据ADD_DEVICE_请求生成一个reducer以更新redux状态，生成一个选择器函数以获取在该状态中更改的变量，然后向组件添加一个prop，该prop等于使用mapstatetops函数生成的选择器的结果

function addDevice(params){
    return (dispatch, getState) => {
        let { authentication } = getState();
        dispatch(request({}));

        service.addDevice(params, authentication.user.access_token)
            .then(
                response => {
                    if(response.status === 201) {
                        dispatch(success(response.data));
                    }
                    return response;
                },
                error => {
                    dispatch(failure(error.toString()));
                    dispatch(alertActions.error(error.toString()));
                }
            )
    }

    function request(response) { return { type: constants.ADD_DEVICE_REQUEST, response } }
    function success(response) { return { type: constants.ADD_DEVICE_SUCCESS, response } }
    function failure(error) { return { type: constants.ADD_DEVICE_FAILURE, error } }
}

function addDevice(params, token){
    return axios({
        url: 'http://localhost:5000/user/add-device',
        method: 'POST',
        headers: { 'Authorization': 'Bearer ' + token},
        data: {
            data1: params.data1,
            data2: params.data2,
            data3: params.data3
        }
    })
    .then(function(response) {
        return response;
    })
    .catch(function(error) {
        return error.response;
    });
}

let response = dispatch(actions.addDevice(params)) 

handleSubmit = (e) => {
   e.preventDefault()
   const { validateFields } = this.props.form;

   validateFields(async (err, params) => {
       if (!err) {
            const { user, dispatch } = this.props;

            let response =await dispatch(actions.addDevice(params))
            console.log(response); //Response is undefined
       }
    });
}

handleSubmit = (e) => {
   e.preventDefault()
   const { validateFields } = this.props.form;

   validateFields((err, params) => {
       if (!err) {
            const { user, dispatch } = this.props;

            dispatch(actions.addDevice(params)).then((response)=>{
                  console.log(response);
            })
       }
    });
}

function addDevice(params){
    return (dispatch, getState) => {
        let { authentication } = getState();
        dispatch(request({}));

        return service.addDevice(params, authentication.user.access_token)
            .then(
                response => {
                    if(response.status === 201) {
                        dispatch(success(response.data));
                    }
                    return response;
                },
                error => {
                    dispatch(failure(error.toString()));
                    dispatch(alertActions.error(error.toString()));
                }
            )
    }

    function request(response) { return { type: constants.ADD_DEVICE_REQUEST, response } }
    function success(response) { return { type: constants.ADD_DEVICE_SUCCESS, response } }
    function failure(error) { return { type: constants.ADD_DEVICE_FAILURE, error } }
}