我正在尝试将 firebase 添加到我的 flutter 项目中，但我不断收到此错误找不到方法实现（）

Question

**This is the error message :** 

Launching lib\main.dart on sdk gphone x86 in debug mode...
Running Gradle task 'assembleDebug'...

FAILURE: Build failed with an exception.

* Where:
Build file 'C:\Users\HP-LinkR\Videos\event_notifier\android\build.gradle' 
 line: 35

* What went wrong:
A problem occurred evaluating root project 'android'.
> Could not find method implementation() for arguments 

[com.android.support:support-annotations:28.0.0] on object of type

org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler.

* 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 2s
Exception: Gradle task assembly debug failed with exit code 1



***This is code for the Build.gradle file that is giving the error:***
    New Properties methods is highlighted red

This is code for the Build.gradle file that is giving the error: New Properties methods is highlighted red This is code for the Build.gradle file that is giving the error: New Properties methods is highlighted red

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: '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.example.event_notifier"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName

        multiDexEnabled true
    }

    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 'com.google.firebase:firebase-analytics:17.2.2'
    compile 'com.android.support:multidex:1.0.1'
}

Answer 1

Goto event_notifier\android\build.gradle ...

These dependencies should make it build:

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib- 
jdk7:$kotlin_version"
    compile "com.google.firebase:firebase-analytics:17.2.2"
    compile "com.android.support:multidex:1.0.1"
}

The actual problem seems to be a quite outdated version of the Android Gradle Plugin.

You'd have to upgrade to something more current to use implementation :

classpath "com.android.tools.build:gradle:4.0.1"

And maybe already start with current androidx packages...because else you'll be stuck at the latest version of Firebase libraries, which use these obsolete support libraries. That Flutter project may generally be outdated and might require some refactoring (unless using the above compile ):

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib:1.3.72"
    implementation "com.google.firebase:firebase-analytics:17.4.4"

    // https://mvnrepository.com/artifact/androidx.multidex/multidex
    implementation "androidx.multidex:multidex:2.0.1"
}