Flutter应用启动崩溃：Activity类找不到实例化异常求助

崩溃日志 #

E/AndroidRuntime(11852):FATAL EXCEPTION: main
E/AndroidRuntime(11852):java.lang.RuntimeException: 无法实例化Activity ComponentInfo{com.name.name/com.name.name.name}: java.lang.ClassNotFoundException: 在路径DexPathList[[zip文件"/data/app/com.portal.name-nCBiBcVsHFUgEAoWt_8Nbw==/base.apk"],]上未找到类"com.name.name.name"

相关配置文件 #

app/build.gradle #

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'
}

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

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
apply plugin: 'com.google.gms.google-services'

android {
compileSdkVersion 33

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

lintOptions {
disable 'InvalidPackage'
    }

defaultConfig {
TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
applicationId "com.name.name"
minSdkVersion 24
targetSdkVersion 30
versionCode flutterVersionCode.toInteger()
versionName flutterVersionName
multiDexEnabled true
manifestPlaceholders = [
appAuthRedirectScheme: 'com.name.name'
        ]
    }

    /*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
        }
    }*/

signingConfigs {
release {
keyAlias keystoreProperties['keyAlias']
keyPassword keystoreProperties['keyPassword']
storeFile keystoreProperties['storeFile'] ? file(keystoreProperties['storeFile']) : null
storePassword keystoreProperties['storePassword']
        }
    }
buildTypes {
release {
multiDexKeepProguard file('multidex-config.pro')
signingConfig signingConfigs.release
        }
    }
}

flutter {
source '../..'
}

dependencies {
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
def multidex_version = "2.0.1"
implementation "androidx.multidex:multidex:$multidex_version"
implementation 'com.google.firebase:firebase-core:12.0.1'
}

android/build.gradle #

buildscript {
    ext.kotlin_version = '1.6.21'
    repositories {
        google()
        jcenter()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:7.2.1'
        // classpath 'com.android.tools.build:gradle:4.0.1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.google.gms:google-services:4.3.10'
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

rootProject.buildDir = '../build'
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(':app')
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

核心问题是指定的Activity类未被找到，按以下步骤修复：

1. 校验Activity注册正确性 #

• 打开AndroidManifest.xml，检查注册的Activity全类名com.name.name.name是否与实际Kotlin/Java文件的包名、类名完全一致，注意拼写和大小写错误
• 确认该Activity类文件确实存在于src/main/kotlin或src/main/java的对应包路径下

2. 修复MultiDex分包配置 #

虽然已开启multiDexEnabled true，但release模式下可能出现类未被包含进主Dex的情况：

• 检查multidex-config.pro文件，确保缺失的Activity类被加入保留列表，添加规则：

  -keep class com.name.name.name { *; }
  

• 若没有该文件，直接创建并添加上述规则，同时确保buildTypes.release中正确引用了该文件

3. 升级兼容依赖版本 #

• 当前firebase-core:12.0.1版本过旧，与gradle插件7.2.1、kotlin 1.6.21存在兼容风险，建议升级至com.google.firebase:firebase-core:21.1.1
• 修改android/build.gradle中的ext.kotlin_version为1.7.10，适配gradle 7.2.1版本

4. 清理重建项目 #

• 执行命令：flutter clean清理构建缓存
• 执行命令：flutter pub get重新拉取依赖
• 重启Android Studio后重新构建运行

5. 统一包名配置 #

报错中出现两个不一致的包名：com.name.name（applicationId）和com.portal.name（apk路径）：

• 检查local.properties、AndroidManifest.xml、app/build.gradle中的applicationId是否统一为com.name.name
• 确认pubspec.yaml中的android.applicationId与上述配置保持一致

内容的提问来源于stack exchange，提问作者Bekzat Zamirbekov