React native:位置0的JSON中的意外令牌

时间:2019-01-13 12:42:17

标签: reactjs react-native npm react-navigation

我是新来的本地人。我想用反应导航创建一个项目。我收到此错误:

SyntaxError: Unexpected token   in JSON at position 0
at JSON.parse (<anonymous>)
at FileStore.get(:\Users\fz\Documents\androidproject\test2\node_modules\metro-cache\src\stores\FileStore.js:26:19)
at C:\Users\fz\Documents\androidproject\test2\node_modules\metro-cache\src\Cache.js:76:40
at Generator.next (<anonymous>)
at step (C:\Users\fz\Documents\androidproject\test2\node_modules\metro-cache\src\Cache.js:18:30)
at C:\Users\fz\Documents\androidproject\test2\node_modules\metro-cache\src\Cache.js:37:14
at new Promise (<anonymous>)
at C:\Users\fz\Documents\androidproject\test2\node_modules\metro-cache\src\Cache.js:15:12
at Cache.get (C:\Users\fz\Documents\androidproject\test2\node_modules\metro-cache\src\Cache.js:102:7)
at C:\Users\fz\Documents\androidproject\test2\node_modules\metro\src\DeltaBundler\Transformer.js:166:34

这是我的app.js:

import React from 'react';
import Input from './input.js';
import Kalkulator from './kalkulator.js';
import { createBottomTabNavigator, createAppContainer } from 'react-        
        navigation'; // Version can be specified in package.json

const RootStack = createBottomTabNavigator({
    Input: Input,
    Kalkulator: Kalkulator
  }
);

export default createAppContainer(RootStack);

这是我的package.json:

{
  "name": "test2",
  "version": "0.0.1",
  "private": true,
  "scripts": {
  "start": "node node_modules/react-native/local-cli/cli.js start",        
  "test": "jest",
  "android-linux": "react-native bundle --platform android --dev false --      
    entry-file index.js --bundle-output 
    android/app/src/main/assets/index.android.bundle --assets-dest 
    android/app/src/main/res && react-native run-android"
  },
  "dependencies": {
      "react": "16.6.3",
      "react-native": "0.57.8",
      "react-native-gesture-handler": "^1.0.12",
      "react-navigation": "^3.0.9"
   },
   "devDependencies": {
      "babel-jest": "23.6.0",
      "jest": "23.6.0",
      "metro-react-native-babel-preset": "0.51.1",
      "react-test-renderer": "16.6.3"
    },
    "jest": {
      "preset": "react-native"
    }
  }

我尝试在Google上进行搜索,但找不到解决此问题的方法,在构建此项目之前,我曾尝试在以前的项目中使用React导航,这很好,但是为什么现在出现此错误? >

1 个答案:

答案 0 :(得分:2)

我今天陷入了同样的问题。我花了几个小时寻找解决方案。没事。 最后,我做了这样的事情:

尝试运行此命令-

npm start -- --reset-cache

在您的根项目目录中,此错误将得到解决。

此命令的目的是在重置缓存后启动npm。