报错

Unable to load script.Make sure you're either running a metro server(run 'react-native start')or that your bundle 'index.android.bundle' is packaged correctly for release.

原因

没有找到index.android.bundle

方法一

• 创建android/app/src/main/assets文件夹
• 执行命令

react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res  

• 重新执行 react-native run-android

方法二

android/app/build.gradle中设置

project.ext.react = [
        bundleAssetName: 'index.android.bundle',
        bundleInDebug: true,
        bundleInAlpha: true,
        bundleInBeta : true
]

主要是设置bundleInDebug等于true，使得开发时也会打包index.android.bundle