react-redux 的这两个函数里的ownProps 参数是干什么用的？看了文档也没看懂

Question

function mapStateToProps(state, ownProps)
function mapDispatchToProps(dispatch, ownProps)

Answer 1

mapStateToProps函数是将需要的state注入到与此视图数据相关的组件上，其中的参数state是redux中保存的全局状态，ownProps是组件本身自带的属性prop

Footer.js
<FilterLink filter="SHOW_ALL">
FilterLink.js
const mapStateToProps = (state,ownProps)=>{
    return {
        active:ownProps.filter === state.visibilityFilter
    }
}

Answer 2

class Box extends Component {

}

Box = connect(mapStateToProps)(Box);


<Box foo="bar" />

ownProps 就是这里传给被 connect 修饰后的 Box 的 props.

Answer 3

components/Footer.js
import React from 'react'
import FilterLink from '../containers/FilterLink'

const Footer = () => (
<p>

Show:
{' '}
<FilterLink filter="SHOW_ALL">
  All
</FilterLink>
{', '}
<FilterLink filter="SHOW_ACTIVE">
  Active
</FilterLink>
{', '}
<FilterLink filter="SHOW_COMPLETED">
  Completed
</FilterLink>

</p>
)

export default Footer

containers/FilterLink.js
import { connect } from 'react-redux'
import { setVisibilityFilter } from '../actions'
import Link from '../components/Link'

const mapStateToProps = (state, ownProps) => {
return {

active: ownProps.filter === state.visibilityFilter

}
}

const mapDispatchToProps = (dispatch, ownProps) => {
return {

onClick: () => {
  dispatch(setVisibilityFilter(ownProps.filter))
}

}
}

const FilterLink = connect(
mapStateToProps,
mapDispatchToProps
)(Link)

export default FilterLink

看到了components/Footer.js里filter属性了没有，ownProps.filter就是这里来的，ownProps作为第二个参数传递给连接组件的props用的