使用多下拉菜单时获取 react-select selected 选项

Question

我的页面上有两个可用的 react-select 下拉菜单，一个允许用户 select A 或 B，另一个允许他们从“蓝色、黄色、红色".

当他们选择了这些项目时，我想使用它们。现在我只想检查已经 selected 的值，所以我只是将它们打印到屏幕上。对于单个 selection 下拉列表，我已成功使用 github 中的示例代码。如下：

import React from 'react';
import Select from 'react-select';

const options = [
  { value: 'a', label: 'a' },
  { value: 'b', label: 'b' },
];

class App extends React.Component {
  state = {
    selectedOption: null,
  }
  handleChange = (selectedOption) => {
    this.setState({ selectedOption });
    document.write(`Option selected:`, selectedOption.value); //this prints the selected option
  }
  render() {
    const { selectedOption } = this.state;

    return (
      <Select
        value={selectedOption}
        onChange={this.handleChange}
        options={options}
        //isMulti //added when the user can pick more than one
      />
    );
  }
}

我的问题是如何成功地为多选项执行此操作？用户可以 select 任意多个，但是在打印已 selected 的选项时会抛出 'undefined' 错误。我认为这是因为该选项存储在一个数组中，但我不确定。

谢谢大家

Answer 1

您需要更改 handleChange 来处理 isMulti。这是一个例子：

import React, { Component } from 'react';
import { render } from 'react-dom';
import Select from 'react-select';

const options = [
  { value: 'a', label: 'a' },
  { value: 'b', label: 'b' },
];

class App extends React.Component {
  state = {
    selectedOptions: [],
  }

  handleChange = (selectedOptions) => {
    this.setState({ selectedOptions });
  }

  render() {
    const { selectedOptions } = this.state;

    return (
      <React.Fragment>
        <Select
          isMulti
          value={selectedOption}
          onChange={this.handleChange}
          options={options}
        />
      {selectedOptions.map(o => <p>{o.value}</p>)}
      </React.Fragment>
    );
  }
}

render(<App />, document.getElementById('root'));

这是一个工作示例：https://stackblitz.com/edit/react-czf4ib

Answer 2

如果您使用的是 React Hooks，这里是您可以使用 isMulti 属性从 react-select 中获取选定值的方法。

import React, {useState} from 'react';
import Select from 'react-select';
import { useForm } from 'react-hook-form';
import { handleSubmit } = useForm();

const options = [
  { value: 'a', label: 'a' },
  { value: 'b', label: 'b' },
];

const FormComponent = (props) => {
  const [selectedOptions, setSelectedOptions] = useState([]);

  const handleChange = (options) => {
    setSelectedOptions(options);
  };

  const onSubmit = (formData, event) => {
     console.log("Form Data: ", formData)
     console.log("Selected Options: ", selectedOptions)
  }

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <Select
          isMulti = {true}
          options={options}
          closeMenuOnSelect={false}
          onChange={handleChange}/>

     <button type="submit">Save</button>
    </form>
  );
}

希望对您有所帮助！

Answer 3

要在数组中存储值，试试这个 [ "purple", "red", "blue" ]

 handleChange = (selectedOptions) => {
    let catArray = [];
    selectedOptions.map(o => 
       catArray.push(o.value)
   );

   this.setState({selectedOptions:catArray});
}

onChange={this.handleChange}

使用多下拉菜单时获取 react-select selected 选项

Get react-select selected option when using multi dropdown

javascript

reactjs

react-select