使用 react-select 我有下一个问题：无法读取未定义的属性 'value'

Question

我正在使用 react-select。当我 select 从 select 得到一个确定值时，我有下一期

TypeError: Cannot read property 'value' of undefined

此外，从 reducer todoList 获取的值没有显示，我看不到它们。

这是我的代码：

import Select from "react-select";
import "./styles.css";
import { searchTodos } from "../../actions/ServiceActions";

class SelectedTodo extends Component {
  constructor(props) {
    super(props);
    this.state = {
      selectedTodo: ""
    };
    this.handleChange = this.handleChange.bind(this);
  }
  bringTodos = () => {
    //WHEN I'M EXECUTING THESE CODE LINES I CAN'T SEE TODOS VALUES
    return this.props.todoList.map(todo => {
      return (
        <option key={todo._id} value={todo._id}>
          {todo.name}
        </option>
      );
    });
  };

  handleChange = e => {
    this.setState({ selectedTodo: e.target.value });
  };

  componentDidMount() {
    this.props.searchTodos();
  }

  render() {
    const { loading } = this.props;

    if (loading) {
      return <span>...Loading</span>;
    }
    return (
      <Select
        className="form-container"
        classNamePrefix="react-select"
        placeholder="Please, insert a todo"
        value={this.state.selectedTodo}
        onChange={this.handleChange}
        options={this.bringTodos()}
      />
    );
  }
}

function mapState(state) {
  return {
    todoList: state.todosDs.todoList
  };
}
const actions = {
  searchTodos
};
SelectedTodo = connect(
  mapState,
  actions
)(SelectedTodo);

export default SelectedTodo;

预期的行为是下拉列表显示待办事项，当我select输入待办事项值时我没有收到错误

TypeError: Cannot read property 'value' of undefined

Answer 1

我认为正如 react-select 的文档所说

 <Select
    value={selectedOption}
    onChange={this.handleChange}
    options={options}
  />

this.handleChange 将直接 return selected 选项而不是事件对象。

    handleChange = selectedOption => {
    this.setState({ selectedOption });
    console.log(`Option selected:`, selectedOption);
  };

而且我认为您也不需要绑定 handleChange 方法。

Answer 2

包react-select直接returns有值

的json

{label:"ABC", value:"abc"}

改变这个

  handleChange = (e) =>{
  this.setState({selectedTodo: e.target.value});
  }

对此

handleChange = (e) =>{
  this.setState({selectedTodo: e});
  }

使用 react-select 我有下一个问题：无法读取未定义的属性 'value'

Using react-select I've got next issue: Cannot read property 'value' of undefined

javascript

reactjs

redux

redux-form

react-select

使用 react-select 我有下一个问题：无法读取未定义的 属性 'value'

Using react-select I've got next issue: Cannot read property 'value' of undefined

javascript

reactjs

redux

redux-form

react-select

使用 react-select 我有下一个问题：无法读取未定义的属性 'value'