React Native 从端点获得的数据未填充下拉列表

dldeef67  于 2022-12-27  发布在  React
关注(0)|答案(1)|浏览(107)

为什么这不是填充下拉列表，我遵循了一个例子，但它仍然没有填充下拉列表，因为它应该.我得到非常空的下拉列表值.通常数据应该是从端点假脱机，然后填充数据作为下拉列表由最终用户选择.
得到的数据是这样

{
    "error": false,
    "message": "OK",
    "results": [
        {
            "_id": "63a7c7a2e1d05cc8db72f011",
            "country_name": "Nigeria",
            "symbol": "NG",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        },
        {
            "_id": "63a7c7d7e1d05cc8db72f014",
            "country_name": "Ghana",
            "symbol": "GH",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        },
        {
            "_id": "63a7c838e1d05cc8db72f016",
            "country_name": "Uganda",
            "symbol": "UG",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        },
        {
            "_id": "63a7c84be1d05cc8db72f018",
            "country_name": "Tanzania",
            "symbol": "TZ",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        },
        {
            "_id": "63a7c873e1d05cc8db72f01a",
            "country_name": "South Africa",
            "symbol": "ZA",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        }
    ]
}

我的代码如下所示

import {
  ImageBackground,
  Modal,
  ScrollView,
  StyleSheet,
  Text,
  TextInput,
  TouchableOpacity,
  View,
} from 'react-native';
import {Picker} from '@react-native-picker/picker';
import React, {useEffect, useState} from 'react';
import {useNavigation} from '@react-navigation/native';
import BackgroundOpacity from './BackgroundOpacity';

const InternationalPayments = () => {
  const navigation = useNavigation();
  const [getBanks, setGetBanks] = useState([]);
  const [getCountry, setGetCountry] = useState([]);
  const [bank_name, setBank_name] = useState('');
  const [country_name, setCountry_name] = useState('');
  const [country_symbol, setCountry_symbol] = useState('');
  const [bank_code, setBank_code] = useState('');
  const [selectedCountry, setSelectedCountry] = useState();
  const [selectedBank, setSelectedBank] = useState();
  const [modalVisible, setModalVisible] = useState(false);

  getallCountry = async () =>{
    fetch('https://webserver-migospay.onrender.com/api/location/get-country',{
      method:'GET',
      headers:{
        'Content-type': 'application/json'
      },

    }).then(response => response.json())
      .then(responseJson=>{
        setGetCountry(responseJson.results);
        setCountry_name(responseJson.results.country_name);
        setCountry_symbol(responseJson.results.symbol);
      })
  }

  useEffect(()=>{
    getallCountry();
  })

  return (
    <View style={styles.container}>
      <BackgroundOpacity
        display={Platform.OS === 'ios' ? false : modalVisible}
      />
      <View style={styles.space} />
      <ScrollView
        contentContainerStyle={{
          justifyContent: 'space-between',
          alignItems: 'center',
        }}>
        <ImageBackground
          source={{
            uri: 'asset:/logo/bg.JPG',
          }}
          imageStyle={{borderRadius: 6}}
          style={{
            top: -30,
            paddingTop: 95,
            alignSelf: 'center',
            width: 328,
            height: 115,
            borderadius: 9,
            justifyContent: 'center',
            alignSelf: 'center',
            alignItems: 'center',
          }}>
          <View>
            <Text style={styles.accText}>Wallet Balance</Text>
            <Text style={styles.text}> 250,000 </Text>
          </View>
        </ImageBackground>

        <View
          style={{
            borderRadius: 5,
            borderWidth: 1,
            overflow: 'hidden',
            height: 53,
            padding: 0,
            borderColor: '#00BB23',
          }}>
          {
            <Picker
              style={{
                width: 300,
                height: 55,
                borderBottomWidth: 1,
              }}
              itemStyle={{
                fontSize: 25,
                fontFamily: 'Poppins-Medium',
              }}
              
              selectedValue={selectedCountry}
              onValueChange={(value, index) => setSelectedCountry(value)}
              >
              <Picker.Item label="Select Country" />
              {getCountry.map((country,index)=>{ //<=== this is supposed to be where it should populate, but it does not populate it. No idea why.
                <Picker.Item label={country.country_name} value={country.symbol} key={index} />
              })}
            </Picker>
          }
        </View>
        
        <View style={styles.space}/>
        <View
          style={{
            borderRadius: 5,
            borderWidth: 1,
            overflow: 'hidden',
            height: 53,
            padding: 0,
            borderColor: '#00BB23',
          }}>
          {
            <Picker
              style={{
                width: 300,
                height: 55,
                borderBottomWidth: 1,
              }}
              itemStyle={{
                fontSize: 25,
                fontFamily: 'Poppins-Medium',
              }}>
              <Picker.Item label="Select Bank" value="accNum" />
            </Picker>
          }
        </View>
        
        <View style={styles.space2}/>
        <TextInput
          placeholder="Destination Account"
          onChangeText={creditAccount => this.setState({creditAccount})}
          style={styles.input}
        />

        <TextInput
          placeholder=" Amount"
          onChangeText={amount => this.setState({amount})}
          style={styles.input}
        />

        <TextInput
          placeholder=" Narration"
          onChangeText={description => this.setState({description})}
          style={styles.input}
        />

        <TextInput
          placeholder=" Destination Branch Code"
          onChangeText={description => this.setState({description})}
          style={styles.input}
        />

        <TextInput
          placeholder=" Beneficiary Name"
          onChangeText={description => this.setState({description})}
          style={styles.input}
        />

        <View
          style={{
            borderRadius: 5,
            borderWidth: 1,
            overflow: 'hidden',
            height: 35,
            padding: 0,
            top: 10,
            borderColor: '#00BB23',
          }}>
          {
            <Picker
              style={{
                width: 300,
                height: 53,
                borderBottomWidth: 1,
              }}
              itemStyle={{
                fontSize: 25,
                fontFamily: 'Poppins-Medium',
              }}>
              <Picker.Item label="Currency" value="accNum" />
              <Picker.Item label="NGN" value="NGN" />
            </Picker>
          }
        </View>

        <TouchableOpacity
          onPress={() => {
            setModalVisible(true);
          }}
          style={styles.button}>
          <Text style={styles.loginbtn}> Transfer </Text>
        </TouchableOpacity>
        <Modal
          hasBackdrop={true}
          backdropOpacity={0.2}
          backdropColor="black"
          transparent
          visible={modalVisible}
          onRequestClose={() => setModalVisible(false)}>
          <View style={styles.modal}>
            <Text>Hello From Modal</Text>
            <TouchableOpacity>
              <Text>Modal! Modal!</Text>
            </TouchableOpacity>
          </View>
        </Modal>
      </ScrollView>
    </View>
  );
};

export default InternationalPayments;

const styles = StyleSheet.create({
  container: {
    paddingTop: 40,
    flex: 1,
    flexDirection: 'row',
    justifyContent: 'space-between',
  },

  modal: {
    top: '50%',
    height: '50%',
    backgroundColor: '#fff',
  },
  accText: {
    top: -50,
    paddingTop: 10,
    justifyContent: 'center',
    alignItems: 'center',
    fontFamily: 'Poppins-Medium',
    fontSize: 12,
    color: 'white',
    textAlign: 'center',
  },
  text: {
    top: -50,
    fontSize: 20,
    color: 'white',
    textAlign: 'center',
    fontFamily: 'Poppins-Bold',
  },
  input: {
    top: 10,
    width: 300,
    height: 53,
    margin: 10,
    fontSize: 12,
    borderColor: '#00BB23',
    fontFamily: 'Poppins-Bold',
    borderRadius: 5,
    borderWidth: 1,
    marginBottom: 30,
  },

  button: {
    marginTop: 40,
    width: 150,
    height: 50,
    padding: 10,
    borderRadius: 10,
    backgroundColor: '#00BB23',
    alignItems: 'center',
  },

  Regbutton: {
    width: 150,
    height: 52,
    padding: 10,
    borderRadius: 10,
    backgroundColor: '#ffffff',
    alignItems: 'center',
    borderWidth: 2,
    borderColor: '#030303',
  },

  loginbtn: {
    color: '#ffff',
    fontSize: 15,
    fontFamily: 'Poppins-Medium',
  },

  AccountBalance: {
    fontSize: 13,
    fontWeight: 'bold',
    textAlign: 'left',
  },

  loginbtn2: {
    color: '#030303',
    fontSize: 20,
    fontWeight: 'bold',
  },

  logo: {
    width: 150,
    height: 150,
  },

  space: {
    top: 10,
    width: 10,
    height: 20,
  },

  space2: {
    width: 10,
    height: 10,
  },

  imageStyle: {
    flexDirection: 'row',
    justifyContent: 'center',
    padding: 5,
    margin: 2,
    height: 15,
    width: 15,
    resizeMode: 'stretch',
    marginBottom: 8,
    marginTop: 8,
    alignItems: 'center',
  },
});

编辑

我处理了Json输出，并让它返回如下数据

{
    "data": [
        {
            "_id": "63a7c7a2e1d05cc8db72f011",
            "country_name": "Nigeria",
            "symbol": "NG",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        },
        {
            "_id": "63a7c7d7e1d05cc8db72f014",
            "country_name": "Ghana",
            "symbol": "GH",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        },
        {
            "_id": "63a7c838e1d05cc8db72f016",
            "country_name": "Uganda",
            "symbol": "UG",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        },
        {
            "_id": "63a7c84be1d05cc8db72f018",
            "country_name": "Tanzania",
            "symbol": "TZ",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        },
        {
            "_id": "63a7c873e1d05cc8db72f01a",
            "country_name": "South Africa",
            "symbol": "ZA",
            "created_at": "2022-12-25T03:40:49.736Z",
            "__v": 0
        }
    ]
}

此方法应该调用数据

getallCountry = async () =>{
    fetch('https://webserver-migospay.onrender.com/api/location/get-country',{
      method:'GET',
      headers:{
        'Content-type': 'application/json'
      },

    }).then(response => response.json())
      .then(responseJson=>{
        setGetCountry(responseJson.data);
        setCountry_name(responseJson.data.country_name);
        setCountry_symbol(responseJson.data.symbol);
      })
  }

有什么想法吗？

react-native

1条答案

按热度按时间
hjqgdpho

hjqgdpho1#

我解决了错误。大括号太多了，去掉它再打字就解决了错误。
看来如此

<Picker.Item label="Select Country" />
      {getCountry.map((country, index) => (
        <Picker.Item label={country.country_name} value={country.symbol} key={index} />
      ))}
    </Picker>
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