我在我的flutter项目中得到的错误，当实现谷歌的标志在

Question

在这里，我已经实现了谷歌登录。google_sign_in 4.1.4 请帮我找出我在哪里做错了或遗漏了什么.先谢谢了...!

这个错误 Rejecting re-init on previously-failed class java.lang.Class: java.lang.NoClassDefFoundError: Failed resolution of: LandroidxlifecycleLifecycleEventObserver;Izygote64(27656)：在java.lang.Object java.lang.Class.newInstance() (Class.java:-2)

 onTap: () async{

                            _signIn(context)
                                .then((FirebaseUser user) => print(user))
                                .catchError((e) => print(e));

                          },

 final FirebaseAuth _auth = FirebaseAuth.instance;
  final GoogleSignIn _googleSignIn = new GoogleSignIn();

  Future<FirebaseUser> _signIn(BuildContext context) async{
    GoogleSignInAccount googleSignInAccount = await _googleSignIn.signIn(); //crash on this line
    GoogleSignInAuthentication gSA = await googleSignInAccount.authentication;
    final AuthCredential  credential  = GoogleAuthProvider.getCredential(idToken: gSA.idToken, accessToken: gSA.accessToken);
    final AuthResult authResult = await _auth.signInWithCredential(credential);
    final FirebaseUser userDetails = authResult.user;
    ProviderDetails providerInfo = new ProviderDetails(userDetails.providerId);
    List<ProviderDetails> providerData = new List<ProviderDetails>();
    providerData.add(providerInfo);

    UserDetails details = new UserDetails(
      userDetails.providerId,
      userDetails.displayName,
      userDetails.photoUrl,
      userDetails.email,
      providerData,
    );

 Navigator.push(
      context,
      new MaterialPageRoute(
        builder: (context) => new ChooseCollegeScreen(),
      ),
    );

    return userDetails;
}

这里是我的错误日志=========&gt。

Rejecting re-init on previously-failed class java.lang.Class<androidx.activity.ComponentActivity$2>: java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/lifecycle/LifecycleEventObserver;
I/zygote64(27656):   at java.lang.Object java.lang.Class.newInstance() (Class.java:-2)
I/zygote64(27656):   at android.app.Activity android.app.Instrumentation.newActivity(java.lang.ClassLoader, java.lang.String, android.content.Intent) (Instrumentation.java:1175)
I/zygote64(27656):   at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2708)
I/zygote64(27656):   at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2895)
I/zygote64(27656):   at void android.app.ActivityThread.-wrap11(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
I/zygote64(27656):   at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1616)
I/zygote64(27656):   at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:106)
I/zygote64(27656):   at void android.os.Looper.loop() (Looper.java:176)
I/zygote64(27656):   at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6651)
I/zygote64(27656):   at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (Method.java:-2)
I/zygote64(27656):   at void com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run() (RuntimeInit.java:547)
I/zygote64(27656):   at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:824)
I/zygote64(27656): Caused by: java.lang.ClassNotFoundException: Didn't find class "androidx.lifecycle.LifecycleEventObserver" on path: DexPathList[[zip file "/data/app/moon.campushaat.com-_doLzLlPm2QzmtHCYUYAfg==/base.apk"],nativeLibraryDirectories=[/data/app/moon.campushaat.com-_doLzLlPm2QzmtHCYUYAfg==/lib/arm64, /data/app/moon.campushaat.com-_doLzLlPm2QzmtHCYUYAfg==/base.apk!/lib/arm64-v8a, /system/lib64, /system/vendor/lib64]]
I/zygote64(27656):   at java.lang.Class dalvik.system.BaseDexClassLoader.findClass(java.lang.String) (BaseDexClassLoader.java:125)
I/zygote64(27656):   at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String, boolean) (ClassLoader.java:379)
I/zygote64(27656):   at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String) (ClassLoader.java:312)
I/zygote64(27656):   at java.lang.Object java.lang.Class.newInstance() (Class.java:-2)
I/zygote64(27656):   at android.app.Activity android.app.Instrumentation.newActivity(java.lang.ClassLoader, java.lang.String, android.content.Intent) (Instrumentation.java:1175)
I/zygote64(27656):   at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2708)
I/zygote64(27656):   at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2895)
I/zygote64(27656):   at void android.app.ActivityThread.-wrap11(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
I/zygote64(27656):   at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1616)
I/zygote64(27656):   at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:106)
I/zygote64(27656):   at void android.os.Looper.loop() (Looper.java:176)
I/zygote64(27656):   at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6651)
I/zygote64(27656):   at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (Method.java:-2)
I/zygote64(27656):   at void com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run() (RuntimeInit.java:547)
I/zygote64(27656):   at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:824) 

Answer 1

确保你的应用程序 迁移到 androidx.(gradle.properties 文件包含的行 android.useAndroidX=true)

此外，这个错误可能与旧的Android设备上的apk-文件大小（超过64K限制）有关（API < 21）。要么改变 minSdkVersion 至21岁以上，或 配置您的应用程序以适应multidex.

在模块一级 build.gradle 锉刀 multidex 库作为一个依赖关系。

android {
    defaultConfig {
        ...
        minSdkVersion 15 
        targetSdkVersion 29
        multiDexEnabled true
    }
    ...
}

dependencies {
  ...
  implementation 'androidx.multidex:multidex:2.0.1'
}