[fluent -- advanced] packaging

1. Generate key

After writing the application , Finally, it's packed , Because I use Android studio Developed , So directly in Terminal Input ：

keytool -genkey -v -keystore ~/key.jks -keyalg RSA -keysize 2048 -validity 100000 -alias key

Remember here -alias key key Alias , You can change it yourself , eject ：

 Enter the keystore password :  
 Enter the new password again : 
 What is your first and last name ?
  [Unknown]:  knight
 What is the name of your organizational unit ?
  [Unknown]:  knight
 What is the name of your organization ?
  [Unknown]:  knight
 What is the name of your city or area ?
  [Unknown]:  knight
 Your province / City / What is the name of the Autonomous Region ?
  [Unknown]:  knight
 The unit's two letter country / What is the area code ?
  [Unknown]:  C
CN=knight, OU=knight, O=knight, L=knight, ST=knight, C=C Whether it is right ?
  [ no ]:  Y

 Generating  2,048  position RSA Key pairs and self signed certificates  (SHA256withRSA) ( Valid for  100,000  God ):
         CN=knight, OU=knight, O=knight, L=knight, ST=knight, C=C
[ Storing /Users/luguian/key.jks] --> Generate the corresponding signature file 

I copied it to android Under the table of contents .

2. establish key.properties

stay android Create one in the directory key.properties:

3. change build.gradle

-----> increase 
def keystorePropertiesFile = rootProject.file("key.properties")
def keystoreProperties = new Properties()
keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
----->
android {
    
    compileSdkVersion 28

    lintOptions {
    
        disable 'InvalidPackage'
    }
    
    defaultConfig {
    
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId "com.example.flutterdemo"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    -----> increase 
    signingConfigs {
    
        release {
    
            keyAlias keystoreProperties['keyAlias']
            keyPassword keystoreProperties['keyPassword']
            storeFile file(keystoreProperties['storeFile'])
            storePassword keystoreProperties['storePassword']
        }
    }
    buildTypes {
    
        release {
    
            signingConfig signingConfigs.release

            minifyEnabled true
            useProguard true

            // proguard The document is confusing  
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    ------> increase 
}

4. Add obfuscation file

By default ,Flutter Don't confuse or shrink Android host . If you plan to use a third party Java or Android library , You may want to reduce APK Size or protect the code from reverse engineering , That's in android/app/ Add below proguard-rules.pro：

Finally, execute in the project root ：

flutter build apk

Initializing gradle...                                       0.6s
Resolving dependencies...                                    1.3s
Gradle task 'assembleRelease'...                                 
Gradle task 'assembleRelease'... Done                        7.2s
Built build/app/outputs/apk/release/app-release.apk (15.8MB).

The final output is build-app-release Next ：

And it worked .

ios How to pack , Please check flutter.dev/docs/deploy….