React-Native:Looks like you installed react-native globally, maybe you meant react-native-cli?

初学RN，跑公司老项目都跑不起来，QAQ哭，如果你是和我一样，新建项目是可以跑的，运行一切正常，但是想运行老项目出现了Looks like you installed react-native globally, maybe you meant react-native-cli? 底下提示

npm uninstall -g react-native
npm install -g react-native-cli

这种情况的，此篇文章可能可以帮到你，但是会更改原来代码的配置，建议咨询大佬，如果你是喜欢瞎折腾的，可以继续看下去。因为上面的提示，所以我就跑这两个命令跑了十几遍，但是每次react-native run-android还是会出现上面的提示，搜索的话也没搜到。下面这篇文章给了我启发

https://segmentfault.com/a/1190000004278414?utm_source=tag-newest

官方文档要求全局安装react-native-cli，但是局部安装react-native，那么会不会是该项目局部安装的react-native，在电脑上是没有的，我们替换成有的就行了。看了下老项目的配置

"dependencies": {
    "antd-mobile": "^2.0.2",
    "dva": "^2.0.3",
    "native-echarts": "^0.3.0",
    "react": "16.0.0-alpha.6",
    "react-dom": "^16.0.0",
    "react-native": "0.44.3",
    "react-native-input-scroll-view": "^1.6.0",
    "react-native-linear-gradient": "^2.3.0",
    "react-native-vector-icons": "^4.4.2",
    "react-navigation": "^1.0.0-beta.13"
  },
  "devDependencies": {
    "babel-jest": "21.2.0",
    "babel-plugin-import": "^1.6.2",
    "babel-preset-react-native": "4.0.0",
    "jest": "21.2.1",
    "react-test-renderer": "16.0.0-alpha.6"
  }

这个是老项目的配置，对比了我新建的项目，的确有很多看着挺老的了，接下来就是升级，我是用webstorm点开Setting可以直接升级配置

File => Settings=>  Languages & Frameworks => Node.js and NPM

最好不要单独升级react-native能升的就升级吧，因为，单独升级了react-native，他的android的依赖，和compileSdkVersion都是会变化的，比如升级后用的v7的包是28.0.0然而其他未升级的，react-native-vector-icons里面用的v7的包是26+的。会冲突。应该也可以直接在package.json直接修改版本号。底下是我修改后的：

"dependencies": {
    "antd-mobile": "2.2.11",
    "dva": "2.4.1",
    "native-echarts": "^0.3.0",
    "react": "16.8.6",
    "react-dom": "16.8.6",
    "react-native": "0.58.6",
    "react-native-input-scroll-view": "^1.6.0",
    "react-native-linear-gradient": "2.5.4",
    "react-native-vector-icons": "6.4.2",
    "react-navigation": "3.7.1"
  },
  "devDependencies": {
    "babel-jest": "24.7.1",
    "babel-plugin-import": "1.11.0",
    "babel-preset-react-native": "4.0.1",
    "jest": "24.7.1",
    "react-test-renderer": "16.8.6"
  },
  "jest": {
    "preset": "react-native"
  }

对于写过android原生的来说，接下来就好改了，升级版本库一般都要修改一些东西，classpath，gradle，v7，compileversion，等等。

项目下android\gradle\wrapper\gradle-wrapper.propertiesapp把gradle改成可用已有的版本，能节省大量时间

distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip

我的是4.1，你的可以看看新建的项目里是什么

项目下的android\build.gradle里的classpath也要更改成对应的

dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }

修改项目下android\app\build.gradle里的，compileSdkVersion和buildToolsVersion以及targetSdkVersion，然后是依赖里的v7包版本号改成28.0.0，把compile改成implementation

android {
    compileSdkVersion 28
    buildToolsVersion "28.0.2"
    defaultConfig {
        applicationId "com.gngcapp"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        ndk {
            abiFilters "armeabi-v7a", "x86"
        }
    }
    ....
}

dependencies {
    implementation project(':react-native-linear-gradient')
    implementation project(':react-native-vector-icons')
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "com.android.support:appcompat-v7:28.0.0"
    implementation "com.facebook.react:react-native:+"  // From node_modules
}

诶，还是改原生的舒服，RN学的我有点头疼，哦对在项目下android\build.gradle里的allprojects添加google仓库，会跑安卓原生的，用android studio编译运行的话，就会有添加提示，假如不添加google仓库跑起来就是

Could not resolve all files for configuration ':app:debugCompileClasspath'.
> Could not find com.android.support:appcompat-v7:28.0.0.
  Searched in the following locations:
      file:/D:/ASSDK/extras/m2repository/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.pom
      file:/D:/ASSDK/extras/m2repository/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.jar
      file:/D:/ASSDK/extras/google/m2repository/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.pom
      file:/D:/ASSDK/extras/google/m2repository/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.jar
      file:/D:/ASSDK/extras/android/m2repository/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.pom
      file:/D:/ASSDK/extras/android/m2repository/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.jar
      file:/C:/Users/ZhuHui/.m2/repository/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.pom
      file:/C:/Users/ZhuHui/.m2/repository/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.jar
      https://jcenter.bintray.com/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.pom
      https://jcenter.bintray.com/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.jar
      file:/H:/gngcApp/node_modules/react-native/android/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.pom
      file:/H:/gngcApp/node_modules/react-native/android/com/android/support/appcompat-v7/28.0.0/appcompat-v7-28.0.0.jar

会提示无法找到28.0.0的v7包，底下是增加的 

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

这样，我的老项目就在安卓手机里跑起来了，嗯，虽然是红色的，连接不到服务器，需要改下ip地址和端口，这个搜一下网上很多