I am trying to build a plain registeration screen in flutter .It is a fairly simply one just to get a grip off fireBase.I incorporated all the fireBase packages did the required changes in the build.gradle files.I think there is an error saying incompatible version but I tried downgrading it still it didnt work. I get this error:-

Running "flutter pub get" in firebase...
Launching lib\main.dart on sdk gphone x86 arm in debug mode...
Running Gradle task 'assembleDebug'...
D8: Cannot fit requested classes in a single dex file (# methods: 94216 > 65536)
com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: 
The number of method references in a .dex file cannot exceed 64K.
Learn how to resolve this issue at https://developer.android.com/tools/building/multidex.html
    at com.android.builder.dexing.D8DexArchiveMerger.getExceptionToRethrow(D8DexArchiveMerger.java:132)
    at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:119)
    at com.android.build.gradle.internal.transforms.DexMergerTransformCallable.call(DexMergerTransformCallable.java:102)
    at com.android.build.gradle.internal.tasks.DexMergingTaskRunnable.run(DexMergingTask.kt:432)
    at com.android.build.gradle.internal.tasks.Workers$ActionFacade.run(Workers.kt:242)
    at org.gradle.workers.internal.AdapterWorkAction.execute(AdapterWorkAction.java:57)
    at org.gradle.workers.internal.DefaultWorkerServer.execute(DefaultWorkerServer.java:63)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1.create(NoIsolationWorkerFactory.java:67)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1.create(NoIsolationWorkerFactory.java:63)
    at org.gradle.internal.classloader.ClassLoaderUtils.executeInClassloader(ClassLoaderUtils.java:97)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1.lambda$execute$0(NoIsolationWorkerFactory.java:63)
    at org.gradle.workers.internal.AbstractWorker$1.call(AbstractWorker.java:44)
    at org.gradle.workers.internal.AbstractWorker$1.call(AbstractWorker.java:41)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:200)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:195)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:75)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:68)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:153)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:68)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:62)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.lambda$call$2(DefaultBuildOperationExecutor.java:76)
    at org.gradle.internal.operations.UnmanagedBuildOperationWrapper.callWithUnmanagedSupport(UnmanagedBuildOperationWrapper.java:54)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:76)
    at org.gradle.workers.internal.AbstractWorker.executeWrappedInBuildOperation(AbstractWorker.java:41)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1.execute(NoIsolationWorkerFactory.java:60)
    at org.gradle.workers.internal.DefaultWorkerExecutor.lambda$submitWork$2(DefaultWorkerExecutor.java:200)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.runExecution(DefaultConditionalExecutionQueue.java:215)
    at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.runBatch(DefaultConditionalExecutionQueue.java:164)
    at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.run(DefaultConditionalExecutionQueue.java:131)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
    at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete, position: null
    at Version.fakeStackEntry(Version_2.1.62.java:0)
    at com.android.tools.r8.utils.Y.a(SourceFile:78)
    at com.android.tools.r8.D8.run(D8.java:11)
    at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:117)
    ... 36 more
Caused by: com.android.tools.r8.utils.b: Cannot fit requested classes in a single dex file (# methods: 94216 > 65536)
    at com.android.tools.r8.utils.T0.error(SourceFile:1)
    at com.android.tools.r8.utils.T0.a(SourceFile:2)
    at com.android.tools.r8.dex.P.a(SourceFile:740)
    at com.android.tools.r8.dex.P$h.a(SourceFile:7)
    at com.android.tools.r8.dex.b.a(SourceFile:14)
    at com.android.tools.r8.dex.b.b(SourceFile:25)
    at com.android.tools.r8.D8.d(D8.java:133)
    at com.android.tools.r8.D8.b(D8.java:1)
    at com.android.tools.r8.utils.Y.a(SourceFile:36)
    ... 38 more


FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:mergeDexDebug'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
   > com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: 
     The number of method references in a .dex file cannot exceed 64K.
     Learn how to resolve this issue at https://developer.android.com/tools/building/multidex.html

* 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 54s
[!] The shrinker may have failed to optimize the Java bytecode.
    To disable the shrinker, pass the `--no-shrink` flag to this command.
    To learn more, see: https://developer.android.com/studio/build/shrink-code
Exception: Gradle task assembleDebug failed with exit code 1

Main.dart

import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:modal_progress_hud_nsn/modal_progress_hud_nsn.dart';
void main() async{
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);
  final String title;
  @override
  State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
  bool showSpinner = false;
  late String email;
  late String Password;
  int _counter = 0;
  final _auth=FirebaseAuth.instance;
  void _incrementCounter() {
    setState(() {
      _counter  ;
    });
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
            TextField(
              textAlign: TextAlign.center,
              onChanged: (value){
                email = value;
              },
              autofocus: true,
            ),
            TextField(
              obscureText: true,
              textAlign: TextAlign.center,
              onChanged: (value){
                Password = value;
              },
              autofocus: true,
            ),
            FlatButton(

              onPressed: () async{
                try{
                  final newUser =  await _auth.createUserWithEmailAndPassword(email: email, password: Password);
                  if(newUser!=null)//check if there is a user registered
                      {
                          print('Registered');//go to the chat screen
                  }
                  setState(() {
                    showSpinner =false;//after a certain amount of time the spinner(buffer)should stop so after going to next screen stop it
                  });
                }
                catch(e){
                print(e);
                }
              },
              child: const Text('Register'),
              color:Colors.blueAccent
            )
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

Pubspec.yaml

name: firebase
description: A new Flutter project.

# The following line prevents the package from being accidentally published to
# pub.dev using `flutter pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a  .
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0 1

environment:
  sdk: ">=2.12.0 <3.0.0"

# Dependencies specify other packages that your package needs in order to work.
# To automatically upgrade your package dependencies to the latest versions
# consider running `flutter pub upgrade --major-versions`. Alternatively,
# dependencies can be manually updated by changing the version numbers below to
# the latest version available on pub.dev. To see which dependencies have newer
# versions available, run `flutter pub outdated`.
dependencies:
  flutter:
    sdk: flutter


  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.2
  firebase_core:
  firebase_auth:
  cloud_firestore:
  animated_text_kit:
  modal_progress_hud_nsn: ^0.1.0-nullsafety-1


dev_dependencies:
  flutter_test:
    sdk: flutter

  # The "flutter_lints" package below contains a set of recommended lints to
  # encourage good coding practices. The lint set provided by the package is
  # activated in the `analysis_options.yaml` file located at the root of your
  # package. See that file for information about deactivating specific lint
  # rules and activating additional ones.
  flutter_lints: ^1.0.0

# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #   - images/a_dot_burr.jpeg
  #   - images/a_dot_ham.jpeg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages

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'
}

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

android {
    compileSdkVersion 30

    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.firebase"
        minSdkVersion 16
        targetSdkVersion 30
        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"
    implementation platform('com.google.firebase:firebase-bom:28.4.2')
    implementation 'com.google.firebase:firebase-analytics'
}

Build.gradle 2

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:4.1.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.google.gms:google-services:4.3.10'
    }
}

allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

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

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

CodePudding user response：

In your build.gradle file, add this line to defaultConfig:

    defaultConfig {
        applicationId "com.example.firebase"
        minSdkVersion 16
        targetSdkVersion 30
        multiDexEnabled true // <-- add this line
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
    }