React-redux useDispatch() Uncaught TypeError

问题

I'm trying to create a simple component to dispatch an action using the React Redux hook useDispatch - and I'm getting an error. I've trimmed the component down to where the error occurs. It happens when the useDispatch function is called.

import { useDispatch } from 'react-redux'

const MyComp = () => {
  useDispatch()
  return null
}

export default MyComp

This is the error I'm seeing in dev console:

Uncaught TypeError: Object(...) is not a function
    at MyComp (MyComp.js?cc4c:4)
    at renderWithHooks (react-dom.development.js?d018:12938)
    at mountIndeterminateComponent (react-dom.development.js?d018:15020)
    at beginWork (react-dom.development.js?d018:15625)
    at performUnitOfWork (react-dom.development.js?d018:19312)
    at workLoop (react-dom.development.js?d018:19352)
    at HTMLUnknownElement.callCallback (react-dom.development.js?d018:149)
    at Object.invokeGuardedCallbackDev (react-dom.development.js?d018:199)
    at invokeGuardedCallback (react-dom.development.js?d018:256)
    at replayUnitOfWork (react-dom.development.js?d018:18578)

I've trimmed this down further so there are no parents in the react tree.

const store = configureStore()

ReactDOM.render(
  <Provider store={store}>
    <MyComp />
  </Provider>,
  document.getElementById('root')
)

Module Versions

    "react": "^16.8.6",
    "react-dom": "^16.8.6",
    "react-redux": "^7.1.0",

回答1:

In my case, I was doing:

import { useDispatch } from 'react'

instead of:

import { useDispatch } from 'react-redux'

🤦‍♂️

回答2:

I got it working - I think by just stopping, building, restarting the app. I didn't expect useDispatch to need this, so I can't explain why that would have helped.

A note - I did try useSelector and that did work, I could output the useSelector variable to console after import from react-redux (console.log of useDispatch was undefined). I could tell at that point I was on the right version of React, and this was probably a problem of my system.

So, if you are having a similar issue. Try a full react app restart. Confirm you are loading the correct version of react.

回答3:

I'm using @reduxjs/toolkit, and assumed react-redux was already installed.

回答4:

I had a similar issue, and the fix was to update "react-redux". Initial package.json was like this:

"react": "^16.12.0",
"react-dom": "^16.12.0",
"react-redux": "^6.0.1",

The problem disappeared after installing react-redux@7.2.0

回答5:

upgrading from

"react-redux": "6.0.1",

"react-redux": "7.2.0",

fixed it for me

run npm outdated for an overview, and then npm update react-redux to update redux

来源：https://stackoverflow.com/questions/57277698/react-redux-usedispatch-uncaught-typeerror

标签

reactjs

redux

react-redux

react-hooks