找不到变量：在构建时反应

Question

我正在尝试构建我的react应用程序，但是我遇到了一些错误，下面是我遇到的第一个危险信号！

我已经在每个文件中导入了React。

buildscript {
    ext {
        buildToolsVersion = "28.0.3"
        minSdkVersion = 16
        compileSdkVersion = 28
        targetSdkVersion = 28
        supportLibVersion = "28.0.0"
    }
    repositories {
        google()
        jcenter()
        maven {
          url 'https://maven.fabric.io/public'
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.3.2'
        classpath 'com.google.gms:google-services:4.2.0'
        classpath 'com.google.firebase:perf-plugin:1.2.1'
        classpath 'io.fabric.tools:gradle:1.28.1'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        mavenLocal()
        jcenter()
        maven {
            // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm
            url "$rootDir/../node_modules/react-native/android"
        }
        maven { url "https://jitpack.io" }
        maven { url "https://maven.google.com" }
    }
}

subprojects {
    project.configurations.all {
        resolutionStrategy.eachDependency { details ->
            if (details.requested.group == 'com.android.support'
                    && !details.requested.name.contains('multidex') ) {
                details.useVersion "27.1.1"
            }
        }
    }
    afterEvaluate {
        android {
            compileSdkVersion 28
            buildToolsVersion "28.0.3"

            defaultConfig {
                targetSdkVersion 28
            }
        }
    }
}

apply plugin: "com.android.application"
apply plugin: "com.google.firebase.firebase-perf"
apply plugin: 'io.fabric'

import com.android.build.OutputFile

project.ext.react = [
    entryFile: "index.js",

    bundleInDebug: project.hasProperty("bundleInDebug") ? project.getProperty("bundleInDebug") : false,
]

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


def enableSeparateBuildPerCPUArchitecture = false
def enableProguardInReleaseBuilds = false

android {
    compileSdkVersion rootProject.ext.compileSdkVersion

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    defaultConfig {
        applicationId "com.motowektor.pojazdy"
        minSdkVersion rootProject.ext.minSdkVersion
        targetSdkVersion rootProject.ext.targetSdkVersion
        versionCode 1
        versionName "1.0"

        // Needed to support API<21, though there is a small chance proguard shrinks things sufficiently
        multiDexEnabled true
    }
    splits {
        abi {
            reset()
            enable enableSeparateBuildPerCPUArchitecture
            universalApk false  // If true, also generate a universal APK
            include "armeabi-v7a", "x86", "arm64-v8a", "x86_64"
        }
    }
     signingConfigs {
        release {
            if (project.hasProperty('MYAPP_UPLOAD_STORE_FILE')) {
                storeFile file(MYAPP_UPLOAD_STORE_FILE)
                storePassword MYAPP_UPLOAD_STORE_PASSWORD
                keyAlias MYAPP_UPLOAD_KEY_ALIAS
                keyPassword MYAPP_UPLOAD_KEY_PASSWORD
            }
        }
    }
    buildTypes {
        release {
            minifyEnabled enableProguardInReleaseBuilds
             matchingFallbacks = ['release', 'debug']
            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, "arm64-v8a": 3, "x86_64": 4]
            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 {
    implementation project(':react-native-mail')
    implementation project(':react-native-splash-screen')
    implementation project(':react-native-fetch-blob')
    implementation project(':mapbox-react-native-mapbox-gl')
    implementation project(':@react-native-community_async-storage')
    implementation project(':react-native-device-info')
    implementation project(':react-native-camera-kit')
    implementation project(':react-native-vector-icons')
    implementation project(':react-native-gesture-handler')
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "com.facebook.react:react-native:+"  // From node_modules

    implementation project(path: ':react-native-firebase')

    implementation "com.google.firebase:firebase-core:16.0.9"
    implementation "com.google.android.gms:play-services-base:16.1.0"


    implementation('com.google.firebase:firebase-ads:15.0.1') {
      exclude group: 'com.android.support', module: 'customtabs'
    }

    implementation "com.google.firebase:firebase-auth:17.0.0"
    implementation "com.google.firebase:firebase-analytics:16.5.0"
    implementation "com.google.firebase:firebase-perf:17.0.0"
    implementation "com.google.firebase:firebase-config:17.0.0"
    implementation "com.google.firebase:firebase-storage:17.0.0"
    implementation "com.google.firebase:firebase-dynamic-links:17.0.0"
    implementation "com.google.firebase:firebase-database:17.0.0"
    implementation "com.google.firebase:firebase-functions:17.0.0"
    implementation "com.google.firebase:firebase-firestore:19.0.2"
    implementation "com.google.firebase:firebase-messaging:18.0.0"
    implementation('com.crashlytics.sdk.android:crashlytics:2.9.9@aar') {
        transitive = true
    }

    implementation "com.android.support:multidex:1.0.3"
    implementation "com.android.support:customtabs:27.1.1"
    implementation 'me.leolin:ShortcutBadger:1.1.22@aar'
}
task copyDownloadableDepsToLibs(type: Copy) {
    from configurations.compile
    into 'libs'
}

apply plugin: 'com.google.gms.google-services'

那么我该如何解决？

我试图创建一个新项目，安装所有插件并复制MainActivity.java和我的所有React组件，但是它不起作用！

Answer 1

将这一行用于特定的文件到react native中。

import React, {Component} from 'react';