semantic ui在下拉列表中反应默认选定的选项

Question

我想在我的dropdown中选择默认选项。当我添加所选选项但不使用默认选定选项渲染时，下面的代码有效：

render() {
        return (
            <Form onSubmit={this.handleFormSubmit}>
                <Form.Dropdown
                  placeholder="Select Options"
                  fluid multiple selection
                  options={this.state.options}
                  onChange={this.handleMultiChange}
                />
                <Button type="submit">Submit</Button>
            </Form>
        );
    }

我尝试添加defaultSelectedLabel={this.state.selected}。

this.state.selected是一个选项数组，默认选择的值为true：

render() {
        return (
            <Form onSubmit={this.handleFormSubmit}>
                <Form.Dropdown
                  placeholder="Select Options"
                  fluid multiple selection
                  options={this.state.options}
                  onChange={this.handleMultiChange}
                  defaultSelectedLabel={this.state.selected}
                />
                <Button type="submit">Submit</Button>
            </Form>
        );
    }

但我得到以下警告：

Warning: Failed prop type: Invalid prop defaultSelectedLabel supplied to Dropdown.

我对defaultValue道具做了同样的事，但得到了同样的错误

如何在dropdown中获取默认选择的选项？

Answer 1

你离结果不远了。

你可以在defaultValue道具中提供一系列值为the docs said。

defaultValue {number | string | arrayOf}初始值或值数组（如果是多个）。

这是一个例子：

class YourComponent extends Component {
  componentWillMount() {
    this.setState({
      options: [
        {value:'1', text:'A'},
        {value:'2', text:'B'},
        {value:'3', text:'C'},
      ],
      selected: ['1', '2'], // <== Here, the values of selected options
    });
  }

  ...

  render() {
    return (
      <Form onSubmit={this.handleFormSubmit}>
        <Form.Dropdown
          placeholder="Select Options"
          fluid multiple selection
          options={this.state.options}
          onChange={this.handleMultiChange}
          defaultValue={this.state.selected} // <== here the default values
        />
        <Button type="submit">Submit</Button>
      </Form>
    );
  }
}

编辑：Here is a live example

Answer 2

适用于单一选择：

import React, { Component } from 'react';
import { render } from 'react-dom';
import { Form, Button } from 'semantic-ui-react';
import './style.css';

class App extends Component {
  componentWillMount() {
    this.setState({
      options: [
        {value:'1', text:'Lamborghini Aventador 2016'},
        {value:'2', text:'VW Beetle 1971'},
        {value:'3', text:'Ford Mustang'},
      ],
      selected: '1',
    });
  }

  render() {
    return (
      <div>
        <Form onSubmit={this.handleFormSubmit}>
          <Form.Dropdown
            placeholder="Select Options"
            defaultValue={this.state.selected}
            fluid selection
            options={this.state.options}
          />
          <Button type="submit">Submit</Button>
        </Form>
      </div>
    );
  }
}

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