Error: uses-sdk:minSdkVersion 16 cannot be smaller than version 18 declared in library [:flutter_secure_storage]

Question

I downloaded a Flutter project and tried to run it but when I run the project I get the following error message:

C:\Users\A\Desktop\flutter_test2\android\app\src\debug\AndroidManifest.xml Error:
    uses-sdk:minSdkVersion 16 cannot be smaller than version 18 declared in library [:flutter_secure_storage] C:\Users\A\Desktop\flutter_test2\build\flutter_secure_storage\intermediates\merged_manifest\debug\AndroidManifest.xml as the library might be using APIs not available in 16
    Suggestion: use a compatible library with a minSdk of at most 16,
        or increase this project's minSdk version to at least 18,
        or use tools:overrideLibrary="com.it_nomads.fluttersecurestorage" to force usage (may lead to runtime failures)

FAILURE: Build failed with an exception.

EDIT: Here is my android/build.gradle file's content:

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 GradleException("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 plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

android {
    compileSdkVersion flutter.compileSdkVersion
    ndkVersion flutter.ndkVersion

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    kotlinOptions {
        jvmTarget = '1.8'
    }

    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId "com.example.flutter_test2"
        // You can update the following values to match your application needs.
        // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-build-configuration.
        minSdkVersion flutter.minSdkVersion
        targetSdkVersion flutter.targetSdkVersion
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
    }

    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.debug
        }
    }
}

flutter {
    source '../..'
}

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
}

It seems it doesn't specify the minsdkversion directly and refers somewhere else to find it. I don't know if it is a good idea to remove that line and hard code the sdkminversion variable or it's better to edit that in a some different way?

Answer 1

go to project/android/app/build.gradle

you'll see this

defaultConfig {
    // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
    applicationId "com.example.dapp"
    minSdkVersion 16
    targetSdkVersion 30
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
}

Change it to this

defaultConfig {
    // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
    applicationId "com.example.dapp"
    minSdkVersion 18
    targetSdkVersion 30
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
}