react-native: Command `run-android` unrecognized. Maybe caused by npm install

问题

Recently I started getting this issue, when I install a react-native package (eg: react-navigation) into my project, a whole bunch of packages are been removed (including react, react-native i think).

And then when i try to run command "run-android", it says it doesn't recognize.

I recently updated to the latest npm and react-native-cli. Is it something wrong with "npm install"? or react-native?

node version: 8.1.2 <br/>
react-native-cli: 2.0.1 <br/>
react-native: 0.45.1 <br/>
react-navigation: 1.0.0-beta.11

Below are the steps to re-create:

• Step 1 - Create project.

• Step 2 - Run the "run-android" command (This works).

• Step 3 - Install "react-native-navigation" into project.

Notice in the image above. Seems like all the other packages are removed from the project.<br/><br/>

• Step 4 - Try running "run-android" command again. (will fail, but used to work before)

Any idea on what the issue is and any way to solve it?

回答1:

Found the solution here.

At first running npm install didn't work, but then, deleting the package-lock.json file and running npm install did the job.

After that I installed react-navigation package seperately and it worked fine.

回答2:

Here's what worked for me from start to finish.

1. react-native init NavTest (The cli is locally installed with this command)
2. deleted package-lock.json
3. npm install --save react-navigation
4. deleted the generated package-lock.json
5. npm install
6. react-native run android A little ugly, I don't know entirely what happened, but this worked. https://reactnavigation.org/ for sample code to run.

Or Copy this to index.android.js

import React, { Component } from 'react';
import { 
  AppRegistry,
  Button,
} from 'react-native';
import {
  StackNavigator,
} from 'react-navigation';



class HomeScreen extends Component {
  static navigationOptions = {
    title: 'Welcome',
  };
  render() {
    const { navigate } = this.props.navigation;
    return (
      <Button
        title="Go to Jane's profile"
        onPress={() =>
          navigate('Profile', { name: 'Jane' })
        }
      />
    );
  }
}

class ProfileScreen extends Component{
  static navigationOptions = {
    title: 'Jane',
  };
  render() {
    return (null);
  }
}

const NavTest= StackNavigator({
  Home: { screen: HomeScreen },
  Profile: { screen: ProfileScreen },
});

AppRegistry.registerComponent('NavTest', () => NavTest);

来源：https://stackoverflow.com/questions/44629309/react-native-command-run-android-unrecognized-maybe-caused-by-npm-install