Flutter 在启动时崩溃：在路径 DexPathList 上找不到类 .MainActivity

Question

我正在将 Flutter 与为 Android 启用的 MultiDex 构建器一起使用，但遇到了一个非常棘手的问题。我的应用程序运行时没有任何异常，但是当video_player添加包时，它在启动时崩溃了：

FATAL EXCEPTION: main
Process: com.rsg.anygoal, PID: 5883
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.rsg.anygoal/com.rsg.anygoal.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.rsg.anygoal.MainActivity" on path: DexPathList[[zip file "/data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/base.apk"],nativeLibraryDirectories=[/data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/lib/x86, /data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/base.apk!/lib/x86, /system/lib, /vendor/lib]]
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2679)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6494)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
 Caused by: java.lang.ClassNotFoundException: Didn't find class "com.rsg.anygoal.MainActivity" on path: DexPathList[[zip file "/data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/base.apk"],nativeLibraryDirectories=[/data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/lib/x86, /data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/base.apk!/lib/x86, /system/lib, /vendor/lib]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
    at android.app.Instrumentation.newActivity(Instrumentation.java:1174)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2669)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856) 
    at android.app.ActivityThread.-wrap11(Unknown Source:0) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589) 
    at android.os.Handler.dispatchMessage(Handler.java:106) 
    at android.os.Looper.loop(Looper.java:164) 
    at android.app.ActivityThread.main(ActivityThread.java:6494) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 

后来在调查这个问题时，我试图禁用 MultiDex 并且似乎修复了它，但随后添加额外的 flutter 包再次破坏了应用程序，所以我认为这不是严格由 multiDex 引起的并重新启用它。

我在论坛中发现的另一个修复尝试是重命名".MainActivity"为确切的类路径，"com.*...*.MainActivity"但这也无济于事。

希望有人会建议一个可能的解决方案！再留下一些我在调查过程中收集的日志和代码片段，其中可能包含对您有帮助的线索。

完整的 Android logcat 日志：https ://pastebin.com/vPs614jj

Flutter pubspec（故意省略名称和描述）：

FATAL EXCEPTION: main
Process: com.rsg.anygoal, PID: 5883
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.rsg.anygoal/com.rsg.anygoal.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.rsg.anygoal.MainActivity" on path: DexPathList[[zip file "/data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/base.apk"],nativeLibraryDirectories=[/data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/lib/x86, /data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/base.apk!/lib/x86, /system/lib, /vendor/lib]]
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2679)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6494)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
 Caused by: java.lang.ClassNotFoundException: Didn't find class "com.rsg.anygoal.MainActivity" on path: DexPathList[[zip file "/data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/base.apk"],nativeLibraryDirectories=[/data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/lib/x86, /data/app/com.rsg.anygoal-tCKWlQXJD-iwdHtVRl0qqA==/base.apk!/lib/x86, /system/lib, /vendor/lib]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
    at android.app.Instrumentation.newActivity(Instrumentation.java:1174)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2669)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856) 
    at android.app.ActivityThread.-wrap11(Unknown Source:0) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589) 
    at android.os.Handler.dispatchMessage(Handler.java:106) 
    at android.os.Looper.loop(Looper.java:164) 
    at android.app.ActivityThread.main(ActivityThread.java:6494) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 

安卓清单：

version: 1.0.6+16
environment:
  sdk: ">=2.1.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^0.1.2
  intl: ^0.15.8
  firebase_core: ^0.4.3+1
  firebase_admob: ^0.9.0+10
  firebase_analytics: ^5.0.9
  firebase_auth: ^0.15.3
  firebase_crashlytics: ^0.1.2+4
  firebase_performance: ^0.3.1+5
  firebase_remote_config: ^0.3.0+1
  firebase_messaging: ^6.0.9
  firebase_dynamic_links: ^0.5.0+9
  cloud_firestore: ^0.13.0+1
  cloud_functions: ^0.4.1+6
  google_sign_in: ^4.1.1
  provider: ^4.0.1
  data_connection_checker: ^0.3.4
  shared_preferences: ^0.5.6
  flutter_markdown: ^0.3.2
  url_launcher: ^5.4.1
  barcode_scan: ^1.0.0
  qr_flutter: ^3.2.0
  share: ^0.6.3+5
  video_player: ^0.10.11+2

dev_dependencies:
  flutter_test:
    sdk: flutter

flutter:
  fonts:
    - family: Raleway
      fonts:
        - asset: fonts/Raleway-Regular.ttf
  uses-material-design: true

主活动.java：

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="$APP_DOMAIN">
    <application android:name="io.flutter.app.FlutterApplication" android:label="$APP_NAME" android:icon="@mipmap/ic_launcher">
        <activity android:name=".MainActivity" android:launchMode="singleTop" android:theme="@style/LaunchTheme" android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode" android:hardwareAccelerated="true" android:windowSoftInputMode="adjustResize">
            <meta-data android:name="io.flutter.app.android.SplashScreenUntilFirstFrame" android:value="true" />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
            <intent-filter>
                <action android:name="FLUTTER_NOTIFICATION_CLICK" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <meta-data android:name="com.google.android.gms.ads.APPLICATION_ID" android:value="$APP_ADS_ID"/>
        <meta-data
            android:name="com.google.firebase.messaging.default_notification_icon"
            android:resource="@drawable/notification_icon" />
    </application>

    <uses-permission android:name="android.permission.INTERNET"/>
</manifest>

颤振医生输出（XCode 无关紧要）：

Doctor summary (to see all details, run flutter doctor -v):
[?] Flutter (Channel stable, v1.17.5, on Mac OS X 10.15.4 19E287, locale en-BG)
 
[?] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
[!] Xcode - develop for iOS and macOS
    ? Xcode installation is incomplete; a full installation is necessary for iOS development.
      Download at: https://developer.apple.com/xcode/download/
      Or install Xcode via the App Store.
      Once installed, run:
        sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
        sudo xcodebuild -runFirstLaunch
[?] Android Studio (version 3.5)
[?] VS Code (version 1.46.1)
[?] Connected device (1 available)

Answer 1

解决方案： 其简单的解决方案是转到MainActivity.kt并将Package-name与AndroidManifest.xml匹配。

Answer 2

我的发现表明这不是 Flutter 本身的问题，而是在特定的 Flutter 包安装之后发生。升级 Gradle 和 AndroidX 库后，崩溃消失，然后在添加另一个 Flutter 包后重新出现。然后我再次清理（build->clean在 IDE 中） android 项目，它再次被修复。因此，这可能是由于我的环境中存在一些 Gradle 混淆，并且可能只是不时以正确的方式编译某些类。

Answer 3

在“包名称”更改后，我遇到了类似的错误。我的解决方案是：也在 MainActivity.kt 中更新包名称。

简而言之，所有包名称都应该相应地固定。

之后，它是固定的。

Answer 4

如果使用 Android Studio/Flutter 解决此问题的最简单方法是：

1：停止应用程序，然后打开MainActivity.kt：

path : "**android/src/main/kotlin/MainActivity.kt**"

如果 MainActivity 中的包名称与您的应用程序不匹配，请在 MainActivity.kt 中更新它。

2：然后转到“编辑”>“查找”>“在文件中替换”，然后在整个应用程序和所有文件中将以前的包名称替换为新的包名称。在继续下一步之前重新启动 Android Studio。（无效缓存并重新启动）

3:重启后...打开app/src/build.gradle并启用multidex:

defaultConfig {
    applicationId "com.your.apppackage"
    minSdkVersion 28
    targetSdkVersion 30
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
    multiDexEnabled true //add multidex enabled
}

...并且不要忘记在同一个 gradle 文件中添加 multidex 依赖项：

**dependencies {**
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'com.google.android.material:material:1.4.0'
    implementation 'androidx.multidex:multidex:2.0.1' // add it as a dependency here
}

最后使缓存失效并重新启动。( File>Invalidate Caches/Restart)。