Flutter Android Studio Error: couldn't get unknown property 'keystoreProperty'

Question

I'm new to flutter and I'm trying to run my first project without any changes to the source code of the demo app. But I keep getting the following error:

Launching lib\main.dart on SM A115F in release mode...
Running Gradle task 'assembleRelease'...

FAILURE: Build failed with an exception.

* Where:
Build file 'C:\Users\METRO\StudioProjects\helloworld\android\app\build.gradle' line: ??

* What went wrong:
A problem occurred evaluating project ':app'.
> Could not get unknown property 'keystoreProperties' for SigningConfig_Decorated{name=release, storeFile=null, storePassword=null, keyAlias=null, keyPassword=null, storeType=pkcs12, v1SigningEnabled=true, v2SigningEnabled=true, enableV1Signing=null, enableV2Signing=null, enableV3Signing=null, enableV4Signing=null} of type com.android.build.gradle.internal.dsl.SigningConfig.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 5s
Exception: Gradle task assembleRelease failed with exit code 1

I tried everything from upgrading gradle to generating keystore even if I'm just trying to run the project, this is my app\build.gradle file:

def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader('UTF-8') { reader ->
        localProperties.load(reader)
    }
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
    throw new FileNotFoundException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
    flutterVersionCode = '1'
}

def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
    flutterVersionName = '1.0'
}

apply plugin: 'com.android.application'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

android {
    compileSdkVersion 30

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId "com.example.helloworld"
        minSdkVersion 16
        targetSdkVersion 30
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName.toString()
    }
signingConfigs{
    release {
        keyAlias keystoreProperties['key']
        keyPassword keystoreProperties['key password']
        storeFile keystoreProperties['C:\\Users\\METRO\\key.jks'] ? file(keystoreProperties['storeFile']) : null
        storePassword keystoreProperties['store password']
    }
}
    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig signingConfigs.release
        }
    }
}

flutter {
    source '../..'
}
if (project.hasProperty("MyProject.signing")
        && new File(project.property("MyProject.signing")+".gradle").exists()){
    apply from: project.property("MyProject.signing")+".gradle"
}
def keystoreProperties = new Properties()
def keystorePropertiesFile = rootProject.file('key.properties')
if (keystorePropertiesFile.exists()){
    keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
}

And this is my keystore.properties file :

storePassword = store password
keyPassword = key password
keyAlias = key
storeFile = C:\\Users\\METRO\\key.jks

Note: android studio highlights warnings in front of storePassword,keyPassword,keyAlias as unused properties. Is this is the problem ? If it is, how to solve it ? PLEASE help.

Answer 1

You probably missing this block inside project/android/app build.gradle file:

def keystoreProperties = new Properties()
   def keystorePropertiesFile = rootProject.file('key.properties')
   if (keystorePropertiesFile.exists()) {
       keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
   }

It should be just before Android block: