http://www.jianshu.com/p/26bb9a27c77a?utm_campaign=maleskine&utm_content=note&utm_medium=pc_all_hots&utm_source=recommendation

原理就是把 redux 的 store，放在 react 的 context 里

React.js 的 context
动手实现 React-redux（一）：初始化工程
动手实现 React-redux（二）：结合 context 和 store
动手实现 React-redux（三）：connect 和 mapStateToProps
动手实现 React-redux（四）：mapDispatchToProps
动手实现 React-redux（五）：Provider
动手实现 React-redux（六）：React-redux 总结

import React,{Component} from 'react';
import PropTypes from 'prop-types';

export const connect = (mapStateToProps,mapDispatchToProps) => (WrappedComponent) => {
    class Connect extends Component {
        static contextTypes = {
            store: PropTypes.object
        };

        constructor() {
            super();
            this.state = {
                allProps: {}
            }
        }

        componentWillMount() {
            const {store} = this.context;
            this._updateProps();
            store.subscribe(() => {
                this._updateProps();
            })
        }

        _updateProps() {
            const {store} = this.context;
            let stateProps = mapStateToProps ? mapStateToProps(store.getState(),this.props) : {}; // 额外传入 props，让获取数据更加灵活方便
            let dispatchProps = mapDispatchToProps ? mapDispatchToProps(store.dispatch,this.props) : {};
            this.setState({
                allProps: { // 整合普通的 props 和从 state 生成的 props
                    ...stateProps,...dispatchProps,...this.props
                }
            })
        }

        render() {
            return <WrappedComponent {...this.state.allProps}/>;
        }
    }
    return Connect;
};

export class Provider extends Component {
    static propTypes = {
        store: PropTypes.object,children: PropTypes.any
    };

    static childContextTypes = {
        store: PropTypes.object
    };

    getChildContext() {
        return {
            store: this.props.store
        }
    }

    render() {
        return <div>
            {this.props.children}
        </div>
    }
}