快速提问，我正在用 typescript 和 redux 编写一个 React-native 应用程序。尝试 connect() 时遇到错误，似乎找不到错误的解决方案。我假设是我做错了什么，但看了几个小时后还是找不到原因。

错误：

Argument of type '(state: AppStateType) => { user: AppStateType; }' is not assignable to parameter of type 'MapStateToPropsParam<IMapStateToProps, void, {}>'.
  Type '(state: AppStateType) => { user: AppStateType; }' is not assignable to type 'MapStateToProps<IMapStateToProps, void, {}>'.
    Types of parameters 'state' and 'state' are incompatible.
      Type '{}' is not assignable to type 'AppStateType'.
        Property 'username' is missing in type '{}'.

尝试连接（mapStateToProps）时：

export default connect<IMapStateToProps, Object, void>(*mapStateToProps*, mapDispatchToProps)(HomeScreen);

我的 Reducer：

import * as Immutable from 'seamless-immutable';
// our defined @types
import { AppStateType, ActionType } from '../../@types';

const appState: AppStateType = {
    username: '',
    password: '',
    serviceCode: 0,
    fetching: false
};

// enforce that state is immutable
export const initialState = Immutable.from(appState);

const userReducer = (state = initialState, action: ActionType)  => {
    switch (action.type) {
        case 'FETCH_USER':
            state = {
                ...state,
                fetching: false
            };
        break;
        case 'SET_USER':
            state = {
                ...state,
                fetching: false
            };
        break;
        default:
        break;
    }
    return state;
};

export default userReducer;

@types 文件：

// app state type
export type AppStateType = {
    username: '';
    password: '';
    serviceCode: 0;
    fetching: false;
};

export interface InterfaceSetUser {
    type: 'SET_USER';
    payload?: {};
}

export interface InterfaceFetchUser {
    type: 'FETCH_USER';
    payload?: {};
}

export type ActionType = InterfaceSetUser | InterfaceFetchUser;

操作：

import { Dispatch } from 'react-redux';

export function SetUser(user: Object) {
    return function(dispatch: Dispatch<{}>) {
        dispatch({
            type: 'SET_USER',
            payload: user
        });
    };
}

组件：

import * as React from 'react';
import { View, Text } from 'react-native';
import { AppStateType, ActionType } from '../@types';
import { Dispatch, connect } from 'react-redux';
import { SetUser } from './../redux/actions/user.actions';
import { bindActionCreators } from 'redux';

interface IMapStateToProps {
    username: '';
    password: '';
    serviceCode: 0;
    fetching: false;
}

const mapStateToProps = (state: AppStateType) => ({
    user: state
});

const mapDispatchToProps = (dispatch: any) => {
    return bindActionCreators({
        setUser: SetUser
    }, dispatch);
};


class HomeScreen extends React.Component {
    render() {
        return(
            <View>
                <Text>
                    Home Screen
                </Text>
            </View>
        );
    }
}

export default connect<IMapStateToProps, Object, void>(mapStateToProps, mapDispatchToProps)(HomeScreen);

我对 Typescript 和 Redux 还比较陌生，因此无法理解这个问题。您能给我指出正确的方向吗？