App signature in flutter

First, create a keystore

1. Enter the command first:

keytool -genkey -v -keystore ./key.jks -keyalg RSA -keysize 2048 -validity 10000 -alias key

2. Enter relevant parameters as prompted, as shown in the following figure

Second, refer to the keystore (

1. Create a file named /android/key.properties that contains a reference to the keystore:

storePassword=The password entered in the key.jks file created in the first stepkeyPassword=password entered in the key.jks file created in the first stepkeyAlias=key //.jks file name, here we created key.jks, so it is keystoreFile=The storage path of the key.jks file created in the first step, such as: C:/Users//key.jks

Note:

• Keep the file private and do not put it in public source control;
The path in
• storeFile is a relative path starting with /android/app/, so it is recommended to use an absolute path in order to prevent unnecessary errorsli>

2. Configure the signature in gradle

Configure signing for your app by editing the /android/app/build.gradle file

(1)Adddef keystorePropertiesFile = rootProject.file("key.properties")def keystoreProperties = new Properties()keystoreProperties.load(new FileInputStream(keystorePropertiesFile))signingConfigs {release {keyAlias ​​keystoreProperties['keyAlias']keyPassword keystoreProperties['keyPassword']storeFile file(keystoreProperties['storeFile'])storePassword keystoreProperties['storePassword']}}(2) Modify buildTypesbuildTypes {release {signingConfig signingConfigs.releasendk{ // This part must be added, otherwise it may cause the successfully compiled release package to crash on the real machineabiFilters "armeabi-v7a"}}debug {ndk {//It should be added here, otherwise there will be problems with the debug package. The last three are optional. It is recommended to add x86 or some simulators will report errors.abiFilters "armeabi", "armeabi-v7a", "arm64-v8a", "x86"}}}

Note:

The

release package may crash in the real machine because the so file of libflutter of arm64 was not introduced in the package.causing "compatibility" issues on arm64 mobile phones.

The main problem is that the so library is referenced. The arm64cpu architecture is backward compatible, that is, the cpu of the arm64 architecture can use the arm32 .so file.The real reason for the problem is when we reference the so library (the so library is referenced in the referenced third-party library).

Three, turn on obfuscation

Flutter does not enable Android obfuscation by default.

If you use a third-party Java or Android library, maybe you want to reduce the size of the apk file or prevent the code from being reversed.

Configuration Obfuscation

Create a /android/app/proguard-rules.pro file and add the following rules:

#Flutter Wrapper-keep class io.flutter.app.** { *; }-keep class io.flutter.plugin.** { *; }-keep class io.flutter.util.** { *; }-keep class io.flutter.view.** { *; }-keep class io.flutter.** { *; }-keep class io.flutter.plugins.** { *; }Copy code

Note: The above configuration only confuses the Flutter engine library, any other library (such as Firebase) needs to add the corresponding rules.

Enable obfuscation/compression

Open the /android/app/build.gradle file and locate the buildTypes block.

Set minifyEnabled and useProguard to true in the release configuration, and then point the obfuscated file to the previous stepcreated file.

android {...buildTypes {release {signingConfig signingConfigs.releaseminifyEnabled trueuseProguard trueproguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'}}}

Fourth, build a release APK

If you complete the signing steps, the APK will be signed.

Using the command line:

1. cd
2. Run flutter build apk (flutter build will include the --release option by default).

The packaged release APK is located at /build/app/outputs/apk/app-release.apk.

5. Install the release APK on the device

Follow the steps below to install the APK built in the previous step on a connected Android device

1. Connect your Android device to your computer with USB
2. Run cd .
3. Run flutter install .