[REACTJS] 어떻게 선택기에서 JSON의 동적 값을 얻기 위해 반작용 네이티브

어떻게 선택기에서 JSON의 동적 값을 얻기 위해 반작용 네이티브

해결법

1. ---

   1.당신은 당신의 코드에서 몇 가지 문제를 가지고

   당신은 당신의 코드에서 몇 가지 문제를 가지고

   나는 당신의 코드를 일부 변경 한, 이것은 당신이 간식 https://snack.expo.io/@andypandy/picker-example에서 여기에서 볼 수있는 작업 예입니다

   import * as React from 'react';
   import { Text, View, StyleSheet, Alert, Picker } from 'react-native';
   import { Constants } from 'expo';
   
   export default class App extends React.Component {
   
     // add a selectValue to your state to stop the overwriting
     state = {
       PickerValueHolder: [],
       selectedValue: ''
     }
   
     componentDidMount() {
       // remove the return 
      fetch('http://1/Dsenze/userapi/inventory/viewinventorytype', {  
           method: 'POST',
           headers: {
             'Accept': 'application/json',
             'Content-Type': 'application/json',
           },
           body: JSON.stringify({
             "username" :"admin",
             "password" :"admin"
           })
         }).then((response) => response.json())
         .then((responseJson) => {
           // use the inventoryTypeData as it is already an array
           let PickerValueHolder = responseJson.inventoryTypeData;
           this.setState({ PickerValueHolder }); // Set the new state
         })
         .catch((error) => {
           console.error(error);
         });
       }
   
     GetPickerSelectedItemValue=()=>{
       Alert.alert(this.state.PickerValueHolder);
     }
   
     render() {
   
   
       return (
         <View style={styles.container}>
           {<Picker
                   selectedValue={this.state.selectedValue}
                   onValueChange={(itemValue, itemIndex) => this.setState({selectedValue: itemValue})} >
                   { this.state.PickerValueHolder.map((item, key)=>
                     <Picker.Item label={item.name} value={item.name} key={key} />
                   )}
                 </Picker>}
         </View>
       );
     }
   }
   
   const styles = StyleSheet.create({
     container: {
       flex: 1,
       justifyContent: 'center',
       paddingTop: Constants.statusBarHeight,
       backgroundColor: '#ecf0f1',
       padding: 8,
     }
   });
   

2. ---

   2.

   import * as React from 'react';
   import { Text, View, StyleSheet, Alert, Picker } from 'react-native';
   import { Constants } from 'react-native';
   
   export default class AddInventory extends React.Component {
   
     // add a selectValue to your state to stop the overwriting
     state = {
       PickerValueHolder: [],
       selectedValue: ''
     }
   
     componentDidMount() {
       // remove the return 
      fetch('http:///Dsenze/userapi/inventory/viewinventorytype', {  
           method: 'POST',
           headers: {
             'Accept': 'application/json',
             'Content-Type': 'application/json',
           },
           body: JSON.stringify({
             "username" :"admin",
             "password" :"admin"
           })
         }).then((response) => response.json())
         .then((responseJson) => {
           // use the inventoryTypeData as it is already an array
           let PickerValueHolder = responseJson.inventoryTypeData;
           this.setState({ PickerValueHolder }); // Set the new state
         })
         .catch((error) => {
           console.error(error);
         });
       }
   
     GetPickerSelectedItemValue=()=>{
       Alert.alert(this.state.PickerValueHolder);
     }
   
     render() {
   
   
       return (
         <View style={styles.container}>
           {<Picker
                   selectedValue={this.state.selectedValue}
                   onValueChange={(itemValue, itemIndex) => this.setState({selectedValue: itemValue})} >
                   { this.state.PickerValueHolder.map((item, key)=>
                     <Picker.Item label={item.name} value={item.name} key={key} />
                   )}
                 </Picker>}
         </View>
       );
     }
   }
   
   const styles = StyleSheet.create({
     container: {
       flex: 1,
       justifyContent: 'center',
       backgroundColor: '#ecf0f1',
       padding: 8,
     }
   });
   

from https://stackoverflow.com/questions/54784307/how-to-get-json-dynamic-value-in-picker-react-native by cc-by-sa and MIT license