안녕하세요? Flutter 강의 잘 듣고 있습니다.

프로그래밍을 접한지 얼마 안된 사람인데요...

보고 따라하는 중에 한 곳에서 정체되어 더 이상 진행이 안 됩니다.

고민하다가 쪽지를 드립니다.

firebase google 로그인 연동하는 단계에서 오류가 났습니다.

일단 실행하면 LoginPage가 에뮬레이터에 뜨고 logcat에는

2019-03-02 22:04:54.161 5054-5082/com.blome.binstagramflutter E/FA: Failed to load metadata: Metadata bundle is null

2019-03-02 22:04:54.164 5054-5082/com.blome.binstagramflutter E/FA: Failed to load metadata: Metadata bundle is null

2019-03-02 22:04:54.199 5054-5082/com.blome.binstagramflutter E/FA: Failed to load metadata: Metadata bundle is null

2019-03-02 22:04:54.200 5054-5082/com.blome.binstagramflutter E/FA: Failed to load metadata: Metadata bundle is null

2019-03-02 22:04:54.209 5054-5082/com.blome.binstagramflutter E/FA: App is missing ACCESS_NETWORK_STATE permission

2019-03-02 22:04:54.210 5054-5082/com.blome.binstagramflutter E/FA: Failed to load metadata: Metadata bundle is null

2019-03-02 22:04:54.214 5054-5082/com.blome.binstagramflutter E/FA: AppMeasurementReceiver not registered/enabled

2019-03-02 22:04:54.220 5054-5082/com.blome.binstagramflutter E/FA: AppMeasurementService not registered/enabled

2019-03-02 22:04:54.220 5054-5082/com.blome.binstagramflutter E/FA: Uploading is not possible. App measurement disabled

2019-03-02 22:04:54.226 5054-5082/com.blome.binstagramflutter E/FA: Failed to load metadata: Metadata bundle is null

2019-03-02 22:04:54.230 5054-5082/com.blome.binstagramflutter E/FA: Failed to load metadata: Metadata bundle is null

2019-03-02 22:04:54.250 5054-5082/com.blome.binstagramflutter E/FA: Task exception on worker thread: java.lang.IllegalStateException: A required meta-data tag in your app's AndroidManifest.xml does not exist. You must have the following declaration within the element: <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" />: com.google.android.gms.measurement.internal.zzfx.zzs(Unknown Source:593)

이런 에러 메시지가 뜨네요.

구글로그인 버튼을 누르면 앱이 종료되고

2019-03-02 22:09:24.125 5054-5054/com.blome.binstagramflutter E/MethodChannel#plugins.flutter.io/google_sign_in: Failed to handle method call

java.lang.IllegalStateException: A required meta-data tag in your app's AndroidManifest.xml does not exist. You must have the following declaration within the element: <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" />

at com.google.android.gms.common.GooglePlayServicesUtilLight.isGooglePlayServicesAvailable(Unknown Source:17)

at com.google.android.gms.common.GoogleApiAvailabilityLight.isGooglePlayServicesAvailable(Unknown Source:5)

at com.google.android.gms.common.GoogleApiAvailability.isGooglePlayServicesAvailable(Unknown Source:94)

at com.google.android.gms.auth.api.signin.GoogleSignInClient.zze(Unknown Source:9)

at com.google.android.gms.auth.api.signin.GoogleSignInClient.getSignInIntent(Unknown Source:18)

at io.flutter.plugins.googlesignin.GoogleSignInPlugin$Delegate.signIn(GoogleSignInPlugin.java:291)

at io.flutter.plugins.googlesignin.GoogleSignInPlugin.onMethodCall(GoogleSignInPlugin.java:77)

at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:200)

at io.flutter.view.FlutterNativeView.handlePlatformMessage(FlutterNativeView.java:163)

at android.os.MessageQueue.nativePollOnce(Native Method)

at android.os.MessageQueue.next(MessageQueue.java:326)

at android.os.Looper.loop(Looper.java:160)

at android.app.ActivityThread.main(ActivityThread.java:6669)

at java.lang.reflect.Method.invoke(Native Method)

at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

2019-03-02 22:09:24.149 5054-5240/com.blome.binstagramflutter E/AndroidRuntime: FATAL EXCEPTION: GoogleApiHandler

Process: com.blome.binstagramflutter, PID: 5054

java.lang.IllegalStateException: A required meta-data tag in your app's AndroidManifest.xml does not exist. You must have the following declaration within the element: <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" />

at com.google.android.gms.common.GooglePlayServicesUtilLight.isGooglePlayServicesAvailable(Unknown Source:17)

at com.google.android.gms.common.GoogleApiAvailabilityLight.isGooglePlayServicesAvailable(Unknown Source:5)

at com.google.android.gms.common.GoogleApiAvailability.isGooglePlayServicesAvailable(Unknown Source:94)

at com.google.android.gms.common.internal.GoogleApiAvailabilityCache.getClientAvailability(Unknown Source:23)

at com.google.android.gms.common.api.internal.GoogleApiManager$zaa.connect(Unknown Source:216)

at com.google.android.gms.common.api.internal.GoogleApiManager.zab(Unknown Source:47)

at com.google.android.gms.common.api.internal.GoogleApiManager.handleMessage(Unknown Source:173)

at android.os.Handler.dispatchMessage(Handler.java:102)

at android.os.Looper.loop(Looper.java:193)

at android.os.HandlerThread.run(HandlerThread.java:65)

--------- beginning of system

2019-03-02 22:09:24.160 5054-5072/com.blome.binstagramflutter E/flutter: [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:

NoSuchMethodError: The getter 'authentication' was called on null.

Receiver: null

Tried calling: authentication

0 Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)

#1      LoginPage._handleSignIn (package:binstagram_flutter/login_page.dart:52:62)
<asynchronous suspension>
#2      LoginPage.build.<anonymous closure> (package:binstagram_flutter/login_page.dart:26:17)
#3      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:507:14)
#4      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:562:30)
#5      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
#6      TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:242:9)
#7      TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:175:7)
#8      PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:315:9)
#9      PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)
#10     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)
#11     _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:180:19)
#12     _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:158:22)
#13     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:138:7)
#14     _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:101:7)
#15     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:85:7)
#16     _invoke1 (dart:ui/hooks.dart:168:13)
#17     _dispatchPointerDataPacket (dart:ui/hooks.dart:122:5)

이렇게 뜹니다..

--------------------------------------------- -----------------------------------------------------

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 28

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.blome.binstagramflutter"
    minSdkVersion 21
    targetSdkVersion 28
    multiDexEnabled true
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
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"

testImplementation 'junit:junit:4.12'

androidTestImplementation 'androidx.test:runner:1.1.0-alpha4'

androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha4'

implementation 'com.google.firebase:firebase-core:16.0.7'

}

--------------------------------------------- --------------------------------------------------

buildscript {

ext.kotlin_version = '1.3.21'

repositories {

google()

jcenter()

}

dependencies {
    classpath 'com.android.tools.build:gradle:3.3.1'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    classpath 'com.google.gms:google-services:4.2.0'
}

}

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

}

----------------------------------------- ----------------------------------------------

org.gradle.jvmargs=-Xmx1536M

android.useAndroidX=true

android.enableJetifier=true

----------------------------------------------- < 매니페스트 > ---------------------------------------------------

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.blome.binstagramflutter">

<!-- The INTERNET permission is required for development. Specifically,
     flutter needs it to communicate with the running application
     to allow setting breakpoints, to provide hot reload, etc.
-->
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<!-- io.flutter.app.FlutterApplication is an android.app.Application that
     calls FlutterMain.startInitialization(this); in its onCreate method.
     In most cases you can leave this as-is, but you if you want to provide
     additional functionality it is fine to subclass or reimplement
     FlutterApplication and put your custom class here. -->
<application
    android:name="io.flutter.app.FlutterApplication"
    android:label="binstagram_flutter"
    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"
        android:hardwareAccelerated="true"
        android:windowSoftInputMode="adjustResize">
        <!-- This keeps the window background of the activity showing
             until Flutter renders its first frame. It can be removed if
             there is no splash screen (such as the default splash screen
             defined in @style/LaunchTheme). -->
        <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>
    </activity>
</application>

뭐가 잘못된걸까요?