"react-native-video 未定义不是一个对象（评估'_reactNative ...）"

Question

Hi I am trying to use the module react-native-video (or any video player) to get my video to play on my app, but am running into the error:

Undefined is not an object (evaluating '_reactNative.NativeModules.UIManager.RCTVideo.Constants') ![1]: https://image.ibb.co/nFt2cQ/Screen_Shot_2017_08_23_at_3_47_18_AM.png "full error image"

In my index.android.js:

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


export default class demodigpocv3 extends Component {
  constructor(props){
    super(props);
  }
  render() {
    return (
      <View style={styles.container}>
        <Text>Hello World</Text>

          <Video
            source={require('./videotrack.mp4')}
            repeat={false} />

      </View>
    );
  }
}

AppRegistry.registerComponent('demodigpocv3', () => demodigpocv3);

I have ran:

react-native link react-native-video

if I rerun it:

rnpm-install info Android module react-native-video is already linked 
rnpm-install info iOS module react-native-video is already linked 

As the docs ( https://github.com/react-native-community/react-native-video ) suggested, in my android/settings.gradle:

>

*** EDIT, I have replaced the following: rootProject.name = 'demodigpocv3' include ':react-native-video' project(':react-native-video-exoplayer').projectDir = new >File(rootProject.projectDir, '../node_modules/react-native-video/android->exoplayer') include ':app' **** WITH this:

project(':react-native-video').projectDir = new >File(rootProject.projectDir, '../node_modules/react-native-video/android')

For the file android/app/build.gradle :

apply plugin: "com.android.application"

import com.android.build.OutputFile

/**
 * The react.gradle file registers a task for each build variant (e.g. bundleDebugJsAndAssets
 * and bundleReleaseJsAndAssets).
 * These basically call `react-native bundle` with the correct arguments during the Android build
 * cycle. By default, bundleDebugJsAndAssets is skipped, as in debug/dev mode we prefer to load the
 * bundle directly from the development server. Below you can see all the possible configurations
 * and their defaults. If you decide to add a configuration block, make sure to add it before the
 * `apply from: "../../node_modules/react-native/react.gradle"` line.
 *
 * project.ext.react = [
 *   // the name of the generated asset file containing your JS bundle
 *   bundleAssetName: "index.android.bundle",
 *
 *   // the entry file for bundle generation
 *   entryFile: "index.android.js",
 *
 *   // whether to bundle JS and assets in debug mode
 *   bundleInDebug: false,
 *
 *   // whether to bundle JS and assets in release mode
 *   bundleInRelease: true,
 *
 *   // whether to bundle JS and assets in another build variant (if configured).
 *   // See http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-Build-Variants
 *   // The configuration property can be in the following formats
 *   //         'bundleIn${productFlavor}${buildType}'
 *   //         'bundleIn${buildType}'
 *   // bundleInFreeDebug: true,
 *   // bundleInPaidRelease: true,
 *   // bundleInBeta: true,
 *
 *   // whether to disable dev mode in custom build variants (by default only disabled in release)
 *   // for example: to disable dev mode in the staging build type (if configured)
 *   devDisabledInStaging: true,
 *   // The configuration property can be in the following formats
 *   //         'devDisabledIn${productFlavor}${buildType}'
 *   //         'devDisabledIn${buildType}'
 *
 *   // the root of your project, i.e. where "package.json" lives
 *   root: "../../",
 *
 *   // where to put the JS bundle asset in debug mode
 *   jsBundleDirDebug: "$buildDir/intermediates/assets/debug",
 *
 *   // where to put the JS bundle asset in release mode
 *   jsBundleDirRelease: "$buildDir/intermediates/assets/release",
 *
 *   // where to put drawable resources / React Native assets, e.g. the ones you use via
 *   // require('./image.png')), in debug mode
 *   resourcesDirDebug: "$buildDir/intermediates/res/merged/debug",
 *
 *   // where to put drawable resources / React Native assets, e.g. the ones you use via
 *   // require('./image.png')), in release mode
 *   resourcesDirRelease: "$buildDir/intermediates/res/merged/release",
 *
 *   // by default the gradle tasks are skipped if none of the JS files or assets change; this means
 *   // that we don't look at files in android/ or ios/ to determine whether the tasks are up to
 *   // date; if you have any other folders that you want to ignore for performance reasons (gradle
 *   // indexes the entire tree), add them here. Alternatively, if you have JS files in android/
 *   // for example, you might want to remove it from here.
 *   inputExcludes: ["android/**", "ios/**"],
 *
 *   // override which node gets called and with what additional arguments
 *   nodeExecutableAndArgs: ["node"],
 *
 *   // supply additional arguments to the packager
 *   extraPackagerArgs: []
 * ]
 */

apply from: "../../node_modules/react-native/react.gradle"

/**
 * Set this to true to create two separate APKs instead of one:
 *   - An APK that only works on ARM devices
 *   - An APK that only works on x86 devices
 * The advantage is the size of the APK is reduced by about 4MB.
 * Upload all the APKs to the Play Store and people will download
 * the correct one based on the CPU architecture of their device.
 */
def enableSeparateBuildPerCPUArchitecture = false

/**
 * Run Proguard to shrink the Java bytecode in release builds.
 */
def enableProguardInReleaseBuilds = false

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.1"

    defaultConfig {
        applicationId "com.demodigpocv3"
        minSdkVersion 16
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
        ndk {
            abiFilters "armeabi-v7a", "x86"
        }
    }
    signingConfigs {
    release {
    storeFile file(MYAPP_RELEASE_STORE_FILE)
    storePassword MYAPP_RELEASE_STORE_PASSWORD
    keyAlias MYAPP_RELEASE_KEY_ALIAS
    keyPassword MYAPP_RELEASE_KEY_PASSWORD
    }
    }
    splits {
        abi {
            reset()
            enable enableSeparateBuildPerCPUArchitecture
            universalApk false  // If true, also generate a universal APK
            include "armeabi-v7a", "x86"
        }
    }
    buildTypes {
        release {
            minifyEnabled enableProguardInReleaseBuilds
            proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
            signingConfig signingConfigs.release
        }
    }
    // applicationVariants are e.g. debug, release
    applicationVariants.all { variant ->
        variant.outputs.each { output ->
            // For each separate APK per architecture, set a unique version code as described here:
            // http://tools.android.com/tech-docs/new-build-system/user-guide/apk-splits
            def versionCodes = ["armeabi-v7a":1, "x86":2]
            def abi = output.getFilter(OutputFile.ABI)
            if (abi != null) {  // null for the universal-debug, universal-release variants
                output.versionCodeOverride =
                        versionCodes.get(abi) * 1048576 + defaultConfig.versionCode
            }
        }
    }
}

dependencies {
    compile project(':react-native-video')
    compile fileTree(dir: "libs", include: ["*.jar"])
    compile "com.android.support:appcompat-v7:23.0.1"
    compile "com.facebook.react:react-native:+"  // From node_modules
    compile project(':react-native-video')
}

// Run this once to be able to run the application with BUCK
// puts all compile dependencies into folder libs for BUCK to use
task copyDownloadableDepsToLibs(type: Copy) {
    from configurations.compile
    into 'libs'
}

In my MainApplication.java :

package com.demodigpocv3;
import com.brentvatne.react.ReactVideoPackage;

import android.app.Application;

import com.facebook.react.ReactApplication;
import com.brentvatne.react.ReactVideoPackage;
import com.facebook.react.ReactNativeHost;
import com.facebook.react.ReactPackage;
import com.facebook.react.shell.MainReactPackage;
import com.facebook.soloader.SoLoader;

import java.util.Arrays;
import java.util.List;




public class MainApplication extends Application implements ReactApplication {

  private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {
    @Override
    public boolean getUseDeveloperSupport() {
      return BuildConfig.DEBUG;
    }
  };

  @Override
  public ReactNativeHost getReactNativeHost() {
    return mReactNativeHost;
  }

  @Override
  public void onCreate() {
    super.onCreate();
    SoLoader.init(this, /* native exopackage */ false);
  }
  @Override
  protected List<ReactPackage> getPackages() {
      return Arrays.asList(
              new MainReactPackage(),
              new ReactVideoPackage()
      );
  }
}



I have been looking for a solution for a couple days, and would appreciate any help I could get. I have ran all the steps in the docs and am still getting the error. 


Here is a similar stack overflow I have found (https://stackoverflow.com/questions/43130134/react-native-video-android-undefined-is-not-an-object-evaluating-nativemoduel), where the accepted answer is:
"Fixed adding the ReactVideoPackage when creating the ReactInstanceManager

mReactInstanceManager = ReactInstanceManager.builder()
            .setApplication(getApplication())
            .setBundleAssetName("index.android.bundle")
            .setJSMainModuleName("index.android")
            .addPackage(new MainReactPackage())
            .addPackage(new ReactVideoPackage())//<-- this line fixed
            .setUseDeveloperSupport(BuildConfig.DEBUG)
            .setInitialLifecycleState(LifecycleState.RESUMED)
            .build();
"

Where do I add this? I tried adding it into my MainActivity.java file (like this below) but the same error is still there:

    package com.demodigpocv3;

import com.facebook.react.ReactActivity;

public class MainActivity extends ReactActivity {

    /**
     * Returns the name of the main component registered from JavaScript.
     * This is used to schedule rendering of the component.
     */
    mReactInstanceManager = ReactInstanceManager.builder()
            .setApplication(getApplication())
            .setBundleAssetName("index.android.bundle")
            .setJSMainModuleName("index.android")
            .addPackage(new MainReactPackage())
            .addPackage(new ReactVideoPackage())//<-- this line fixed
            .setUseDeveloperSupport(BuildConfig.DEBUG)
            .setInitialLifecycleState(LifecycleState.RESUMED)
            .build();

    @Override
    protected String getMainComponentName() {
        return "demodigpocv3";
    }
}

I would love any solutions, ideally non java solutions (as I don't really know java) and beginner friendly answers/terminology would be preferred.

Answer 1

You have to eject your app from expo and use the bare workflow if you want to use "react-native-video".

Btw, you can use Expo Video instead of react-native-video : https://docs.expo.io/versions/latest/sdk/video/

Answer 2

In "setting.gradle" change
project(':react-native-video-exoplayer').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-video/android-exoplayer') to
project(':react-native-video').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-video/android')

Answer 3

尝试将getPackage（）放入最终的私有类中。