未捕获的TypeError：_this2.props.selectBook不是一个函数，自动复制

Posted 2021-05-03

我在Stackoverflow社区遇到了类似的问题，但问题的答案并没有解决我的困境。在互联网上尝试几乎所有与此问题相关的内容之后，我一直遇到这个问题。所以请回答这个问题，以便在我的开发中取得进展。任何帮助深深感激。

书list.js

import React, { Component } from 'react';
import { connect } from 'react-redux';
import { selectBook } from '../actions/index.js';
import { bindActionCreators } from 'redux';

class BookList extends Component {
    renderList() {
        return this.props.books.map((book) => {
            return (
                <li
                    key={book.title}
                    onClick={() => this.props.selectBook(book)}
                    className="list-group-item">
                    {book.title}
                </li>
            );
        });
    }

    render() {
        return (
            <ul className="list-group col-sm-4">
                {this.renderList()}
            </ul>
        )
    }
}


function mapStateToProps(state) {
    return {
        books: state.books
    };
}

//Anythin returned from this function will end up as props
// on the BookList container
const mapDispatchToProps = (dispatch) => {
    // whenever selectBook is called, the result should be passed
    // to all of our reducers
    return bindActionCreators({ selectBook: selectBook }, dispatch);
}


//Promote BookList from a component to a container - it needs to know
//about this new dispatch method, selectBook. Make ot available
//as a prop.

export default connect(mapStateToProps, mapDispatchToProps)(BookList);

index.js - 减速器

import { combineReducers } from 'redux';
import BooksReducer from './reducer_books';

const rootReducer = combineReducers({
  books: BooksReducer
});

export default rootReducer;

index.js - 动作

function selectBook(book) {
  console.log('A book has been selected', book.title);
}

答案

在这种情况下（和我的）改变这个：

function selectBook(book) {
  console.log('A book has been selected', book.title);
}

至：

export function selectBook(book) {
  console.log('A book has been selected:', book.title);
}

是什么修复它。就像对问题的评论一样，我没有出口selectBook。我不完全确定如何做到这一点;但这是正确的方法。