Hello World does not appear in response to native android

Question

Hi, I made a program Hello Worldin react-nativefor android. I followed this https://facebook.imtqy.com/react-native/docs/tutorial.html#content , but when the application starts, it does not duplicate "Hello World" on the screen.

A blank screen is displayed. How can I fix this problem.

index.android.js

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React, { Component } from 'react';
import {
  AppRegistry,
  Text
} from 'react-native';

export default class AwesomeProject extends Component {
  render() {
    return (
        <Text>Hello World!</Text>
    );
  }
}

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

Build logs

E:\React Programming\AwesomeProject>react-native run-android
Starting JS server...
Running C:\Users\ch-e00925\AppData\Local\Android\sdk/platform-tools/adb -s ZY223
8CX5L reverse tcp:8081 tcp:8081
Building and installing the app on the device (cd android && gradlew.bat install
Debug...
:app:preBuild UP-TO-DATE
:app:preDebugBuild UP-TO-DATE
:app:checkDebugManifest
:app:preReleaseBuild UP-TO-DATE
:app:prepareComAndroidSupportAppcompatV72301Library UP-TO-DATE
:app:prepareComAndroidSupportRecyclerviewV72301Library UP-TO-DATE
:app:prepareComAndroidSupportSupportV42321Library UP-TO-DATE
:app:prepareComFacebookFrescoDrawee0110Library UP-TO-DATE
:app:prepareComFacebookFrescoFbcore0110Library UP-TO-DATE
:app:prepareComFacebookFrescoFresco0110Library UP-TO-DATE
:app:prepareComFacebookFrescoImagepipeline0110Library UP-TO-DATE
:app:prepareComFacebookFrescoImagepipelineBase0110Library UP-TO-DATE
:app:prepareComFacebookFrescoImagepipelineOkhttp30110Library UP-TO-DATE
:app:prepareComFacebookReactReactNative0350Library UP-TO-DATE
:app:prepareComFacebookSoloaderSoloader010Library UP-TO-DATE
:app:prepareOrgWebkitAndroidJscR174650Library UP-TO-DATE
:app:prepareDebugDependencies
:app:compileDebugAidl UP-TO-DATE
:app:compileDebugRenderscript UP-TO-DATE
:app:generateDebugBuildConfig UP-TO-DATE
:app:generateDebugAssets UP-TO-DATE
:app:mergeDebugAssets UP-TO-DATE
:app:generateDebugResValues UP-TO-DATE
:app:generateDebugResources UP-TO-DATE
:app:mergeDebugResources UP-TO-DATE
:app:bundleDebugJsAndAssets SKIPPED
:app:processDebugManifest UP-TO-DATE
:app:processDebugResources UP-TO-DATE
:app:generateDebugSources UP-TO-DATE
:app:processDebugJavaRes UP-TO-DATE
:app:compileDebugJavaWithJavac UP-TO-DATE
:app:compileDebugNdk UP-TO-DATE
:app:compileDebugSources UP-TO-DATE
:app:preDexDebug UP-TO-DATE
:app:dexDebug UP-TO-DATE
:app:validateDebugSigning
:app:packageDebug UP-TO-DATE
:app:zipalignDebug UP-TO-DATE
:app:assembleDebug UP-TO-DATE
:app:installDebug
Installing APK 'app-debug.apk' on 'Moto G (4) - 6.0.1'
Installed on 1 device.

BUILD SUCCESSFUL

Total time: 1 mins 9.699 secs
Starting the app on ZY2238CX5L (C:\Users\ch-e00925\AppData\Local\Android\sdk/pla
tform-tools/adb -s ZY2238CX5L shell am start -n com.awesomeproject/.MainActivity
)...
Starting: Intent { cmp=com.awesomeproject/.MainActivity }

Answer 1

You need to use it first react-native startto run the running package, and then use it react-native run-androidto start the emulator.

Answer 2

, , - . - :

import React, { Component } from 'react';
import { AppRegistry, Text, View } from 'react-native';

class HelloWorldApp extends Component {
  render() {
    return (
      <View style={{ flex: 1, backgroundColor: 'red', alignItems: 'center', justifyContent: 'center' }}>
        <Text>Hello world!</Text>
      </View>
    );
  }
}

AppRegistry.registerComponent('Boxit', () => HelloWorldApp);

Answer 3

The problem is that expo is trying to add a lot of characters to the text

<Text>Hello World!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!</Text>

You will see that the last part will be visible on the top screen. The problem basically is that the text displays (var status hides the text!) If you look, you can see the text in the status bar.