Javascript 我可以在 Redux 中没有 mapStateToProps 的情况下 mapDispatchToProps 吗？
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Can I mapDispatchToProps without mapStateToProps in Redux?
提问by Iggy
I am breaking apart Redux' todo example to try to understand it. I read that mapDispatchToPropsallows you to map dispatch actions as props, so I thought of rewriting addTodo.jsto use mapDispatchToProps instead of calling dispatch(addTodo()). I called it addingTodo(). Something like this:
我正在分解 Redux 的 todo 示例以试图理解它。我读到mapDispatchToProps允许您将调度操作映射为道具，因此我想到重写addTodo.js以使用 mapDispatchToProps 而不是调用 dispatch(addTodo())。我叫它addingTodo()。像这样的东西：
import React from 'react';
import {connect} from 'react-redux';
import addTodo from '../actions';
let AddTodo = ({addingTodo}) => {
let input;
return (
<div>
<form onSubmit={e => {
e.preventDefault()
if (!input.value.trim()) {
return
}
addingTodo(input.value)
input.value = ""
}}>
<input ref={node => {
input = node
}} />
<button type="submit">Submit</button>
</form>
</div>
)
}
const mapDispatchToProps = {
addingTodo: addTodo
}
AddTodo = connect(
mapDispatchToProps
)(AddTodo)
export default AddTodo
However, when I run the app, I get this error: Error: Invalid value of type object for mapStateToProps argument when connecting component AddTodo.. I never used mapStateToPropsto begin with on AddTodo component, so I was not sure what was wrong. My gut feeling says that connect()expects mapStateToPropsto precede mapDispatchToProps.
但是，当我运行该应用程序时，出现以下错误：Error: Invalid value of type object for mapStateToProps argument when connecting component AddTodo.. 我从来没有mapStateToProps开始使用 AddTodo 组件，所以我不确定出了什么问题。我的直觉说，connect()期待mapStateToProps领先mapDispatchToProps。
The working original looks like this:
工作原件如下所示：
import React from 'react';
import {connect} from 'react-redux';
import addTodo from '../actions';
let AddTodo = ({dispatch}) => {
let input;
return (
<div>
<form onSubmit={e => {
e.preventDefault()
if (!input.value.trim()) {
return
}
dispatch(addTodo(input.value))
input.value = ""
}}>
<input ref={node => {
input = node
}} />
<button type="submit">Submit</button>
</form>
</div>
)
}
AddTodo = connect()(AddTodo)
export default AddTodo
Complete repo can be found here.
完整的回购可以在这里找到。
So my question is, is it possible to do mapDispatchToProps without mapStateToProps? Is what I am trying to do an acceptable practice - if not, why not?
所以我的问题是，是否可以在没有 mapStateToProps 的情况下执行 mapDispatchToProps？我正在尝试做的是一种可接受的做法 - 如果不是，为什么不呢？
回答by iofjuupasli
Yes, you can. Just pass nullas first argument:
是的你可以。只需null作为第一个参数传递：
AddTodo = connect(
null,
mapDispatchToProps
)(AddTodo)
Yes, it's not just acceptable practice, it's recommended way to trigger actions. Using mapDispatchToPropsallows to hide the fact of using redux inside your react components
是的，这不仅是可接受的做法，而且是触发操作的推荐方式。使用mapDispatchToProps允许隐藏在 React 组件中使用 redux 的事实
