将本机 Picker 项目列表绑定到获取请求并选择一个项目

Question

需要将从 useEffect() 中的获取请求中获取的运动列表绑定到 react-native Picker，并将 select 来自 picker.item 的运动绑定到变量。使用基于 class 的组件找到。在具有网络绑定和项目 selection

的功能组件中需要一个解决方案

import React, { useState, useEffect } from 'react'
import { Picker } from '@react-native-picker/picker';

// Functional Component
export default function PlayerRegistration() {

// Picker.item List
const [listofsports, setListOfSports] = useState([])
// Selected Item variable
const [selectedItem, setSelectedSport] = useState()

// Fetch Function
 const getListOfPlayersList = () => {
        const api = API();
        console.log('working backendapi', api)
        const sportscentersapi = `${api}/sports`;

        const test = fetch(sportscentersapi, {
            method: 'GET',
            headers: {
                Accept: 'application/json',
                'Content-Type': 'application/json',
            }
        })
            .then(response => response.json())
            .then(data => {
                //console.log(data),
                setListOfSports({ listofsports: data })
            });
    }

// ComponentDidmount or ComponentDidUpdate Equivalent
useEffect(() => {
        getListOfPlayersList();
// Returning list looks similar to this.
//[{ "idsport": 1, "sportname": "Badminton" }, { "idsport": 2,"sportname": "Golf"}]

});

// JSX
    return ( <Picker
                selectedValue={selectedItem}
                onValueChange={(itemValue, itemIndex) =>
                    setSelectedSport(itemValue)
                }>
                {

                listofsports.map((item, index) => {
                    return (<Picker.Item
                        key={index}
                        label={`${item.sportname.toString()}`}
                        value={`${item.sportname}`} />)
                })

                }
            </Picker>)

}

Answer 1

参考这个我得到了一个按预期工作的答案。

import React, { useState, useEffect } from "react";
import { Picker } from "@react-native-picker/picker";

// Functional Component
export default function PlayerRegistration() {
  // Picker.item List
  const [listofSports, setlistofSports] = useState([]);
  // Selected Item variable
  const [selectedValue, setSelectedValue] = useState("");

  // Fetch Function
  const getListOfPlayersList = async () => {
    const api = 'http://localhost:3000';
    console.log("working backendapi", api);
    const sportscentersapi = `${api}/sports`;

    const test = fetch(sportscentersapi, {
       method: "GET",
       headers: {
         'Accept': 'application/json',
         'Content-Type': 'application/json'
       }
    })
       .then((response) => response.json())
       .then((json) => setlistofSports(json.data))
       .catch((error) => console.error(error));
    // Incase if you need static json could use this
    // return [
    //   { idsport: 1, sportname: "Badminton" },
    //   { idsport: 2, sportname: "Golf" }
    // ];
  };

  // ComponentDidmount or ComponentDidUpdate Equivalent
  useEffect(() => {
    getListOfPlayersList();
  }, []);


  const renderSportsList = () => {
    return listofSports.map((sport) => {
      return <Picker.item label={sport.idsport} 
      value={sport.sportname} />;
    });
  };

  // JSX
  return (
     <Picker
       selectedValue={selectedValue}
       style={{ height: 40, width: 150 }}
       onValueChange={(itemValue, itemIndex) => {
         setSelectedValue(itemValue);
       }}
     >
       {renderSportsList()}
     </Picker>
  );
}

将本机 Picker 项目列表绑定到获取请求并选择一个项目

React native Picker item list binding with fetch request and selecting an item

javascript

picker

reactjs

react-native