export default connect(function mapStateToProps(state) {
    return {
        counter:state.counter.count,
        username:state.user.name,
    }
},function mapDispatchToProps(dispatch) {
    return {
        add:(num) => dispatch({ type:'ADD',num }),
        rename:(name) => dispatch({ type:'UPDATE',name })
    }
})(Index)

既然是higher order component，这里可以用装饰器实现吗，感觉这里的代码太复杂了