无法解析 com.facebook.react:react-native:0.32.0

Question

我在 android studio 的 react native 项目中打开了 android 文件夹，对build.gradle 文件进行了所有可能的修改。但是我得到这个重复的错误：

Error:Failed to resolve: com.facebook.react:react-native:0.32.0  

我的package.json如下：

{
  "name": "empty-project-template",
  "private": true,
  "scripts": {
    "start": "react-native start",
    "android": "react-native run-android",
    "ios": "react-native run-ios"
  },
  "dependencies": {
    "eslint": "^3.17.0",
    "expo": "^30.0.1",
    "react": "^16.4.0",
    "react-native": "https://github.com/expo/react-native/archive/sdk-30.0.0.tar.gz",
    "react-native-elements": "^0.19.1",
    "react-native-vector-icons": "^4.2.0",
    "react-router": "^4.3.1"
  }
}   

我的 gradle 文件是：

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: []
 * ]
 */

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

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 27
    buildToolsVersion '28.0.2'

    defaultConfig {
        applicationId "com.sampleprojecttemplate"
        minSdkVersion 16
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        ndk {
            abiFilters "armeabi-v7a", "x86"
        }
    }
    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"
        }
    }
    // 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 {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "com.android.support:appcompat-v7:27.1.1"
    implementation "com.facebook.react:react-native:0.32.0"   // From node_modules
}

// 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'
}

如何解决此错误？我试过了：

implementation "com.facebook.react:react-native:+"  

但这并没有成功。

Answer 1

很奇怪你使用了来自 expo 的 react-native 的打包版本......最重要的是，你的 package.json 似乎指向 0.30 版本？相当过时，目前的RN版本是0.57.2

当对我的构建配置（android 上的 package.json、build.gradle、iOS 上的 podfile 或工作区/项目设置）有疑问时，我会使用 react-native-cli 创建一个虚拟的 react-native 项目，并比较构建用我创建的项目的文件。

• 安装 react-native-cli : npm install -g react-native-cli
• 创建一些测试项目react-native init testProject
• 查看 package.json、build.gradle 并查看与您自己的文件的差异

然后，修复构建：

• 更新 package.json、grade.build 的 dependencies 部分

• 对 package.json 的任何更改都需要 npm install（有时之前需要 rm -rf node_modules，以清除所有节点依赖项）。此外，请确保在您键入该命令时关闭任何可能保留文件缓存版本的 IDE（XCode、Android Studio）

您应该明确地将implementation "com.facebook.react:react-native:0.32.0" 替换为implementation "com.facebook.react:react-native:+"