android - 在颤振应用程序中实现本机 Kotlin 代码时出现“未解决的参考：android”错误

问题描述

我对 android studio 很陌生，并尝试围绕颤振做一些事情。尝试在 MainActivity.kt 中编写一些特定于 android 的代码，并在 android 包下获得红色波浪线。官方 android 开发文档也将此代码发布为正确的导入方法。

    import android.content.Context
    import android.content.ContextWrapper
    import android.content.Intent
    import android.content.IntentFilter
    import android.os.BatteryManager

在 androidx 下也得到相同的波浪形红线。错误相同：找不到参考：adnroidx

    import androidx.annotation.NonNull

谷歌搜索，但到目前为止没有找到任何线索。还尝试创建一个新的颤振项目，并确保检查了对 kotlin 和 swift 的支持，但无济于事。

所以剩下的唯一方法就是询问堆栈溢出社区。

这是android目录中的build.gradle

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

        dependencies {
            classpath 'com.android.tools.build:gradle:3.5.0'
            classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        }
    }

    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
    }

这是 android/app 目录中的 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: 'kotlin-android'
    apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

    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.firstapp"
            minSdkVersion 16
            targetSdkVersion 28
            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:1.1.1'
        androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
    }

标签： androidflutterkotlin

android - 在颤振应用程序中实现本机 Kotlin 代码时出现“未解决的参考：android”错误

问题描述

解决方案

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