javascript - 将 jsx 组件存储在 react-native 的变量中

Question

我试图在 return 方法中打印时将 react-native jsx 元素存储在变量中，但我收到这样的错误:文本字符串必须在组件中呈现。下面是我的代码我收到错误。任何帮助将不胜感激:

import { Text, View, Button } from 'react-native';
import React, { useState } from 'react';

const GameScreen = (props) => {

  const [num, setNum] = useState(0);
  const [randNum, setRandNum] = useState(0);
  const [currentNum, setCurrentNum] = useState('')
  // const [jsxVal, setJsxVal] = useState('')
  let jsxVal = '';

  const setRandomNum = (num, min, max) => {
    const randNum = Math.floor(Math.random() * (max - min)) + min
    setNum(num);
    setRandNum(randNum);
    console.warn("Number is:" + num + " and random number:" + randNum);
  }

  const checkNum = (num) => {
    if (num < randNum) {
      jsxVal = <Text>Your number {num} is lower than {randNum}</Text>;
      console.warn("if")
    } else if (num === randNum) {
      jsxVal = <Text>Your number {num} is greater than {randNum}</Text>;
      console.warn("else if")
    } else {
      jsxVal = <Text>Your number {num} is greater than {randNum}</Text>;
      console.warn("else")
    }
    console.warn("checkNum")
  }

  return (
    <View>
      {
        num === 0 ? setRandomNum(props.navigation.getParam('number'), 1, 100) : null
      }
      <Text>Value is :{num}</Text>
      <View style={{
        justifyContent: 'space-around',
        paddingHorizontal: 8,
        paddingVertical: 8,
        flexDirection: 'row'
      }}>
        <Button title="Lower" onPress={() => { checkNum(num) }} />
        <Button title="Greater" onPress={() => { checkNum(num) }} />
        {
          jsxVal === '' ? null : jsxVal 
        }
      </View>
    </View>
  );
}

export default GameScreen;

Answer 1

首先，您可以让函数返回 jsx 本身:

 checkNum = (num) => {
   if (num < randNum) {
      return(<Text>Your number {num} is lower than {randNum}</Text>);
   } else if (num === randNum) {
     return(<Text>Your number {num} is greater than {randNum}</Text>);
   } else {
     return(<Text>Your number {num} is greater than {randNum}</Text>);
}}

然后，你可以在任何地方调用它们的方法:

 <Button title="Greater" onPress={() => { checkNum(num) }} />
 {this.checkNum(num)}