RN打包前准备

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

IOS:
react-native bundle --entry-file index.js --platform ios --dev false --bundle-output ./ios/bundle/index.ios.jsbundle --assets-dest ./ios/bundle

Duplicate resources报错的话
在 /node_modules/react-native/react.gradle 这个文件里加上

doFirst { ... }
doLast {
    def moveFunc = { resSuffix ->
        File originalDir = file("$buildDir/generated/res/react/release/drawable-${resSuffix}");
        if (originalDir.exists()) {
            File destDir = file("$buildDir/../src/main/res/drawable-${resSuffix}");
            ant.move(file: originalDir, tofile: destDir);
        }
    }
    moveFunc.curry("ldpi").call()
    moveFunc.curry("mdpi").call()
    moveFunc.curry("hdpi").call()
    moveFunc.curry("xhdpi").call()
    moveFunc.curry("xxhdpi").call()
    moveFunc.curry("xxxhdpi").call()
}