解决失败: androidx

Question

我正在使用一个代码库教程https://codelabs.developers.google.com/codelabs/android-room-with-a-view/index.html?index=..%2F..index#3。在编辑buil.gradle (app)时使用的Int。我得到了未能解决: androidx，未能解决: androidx.arch &未能解决: com.google.android

build.gradle

android {
    compileSdkVersion 29
    buildToolsVersion "30.0.1"

    defaultConfig {
        applicationId "com.example.androidroomcodelabs"
        minSdkVersion 21
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility = 1.8
        targetCompatibility = 1.8
    }

}

dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'


    // Room components
    implementation "androidx.room:room-runtime:$rootProject.2.2.4"
    annotationProcessor "androidx.room:room-compiler:$rootProject.2.2.4"
    androidTestImplementation "androidx.room:room-testing:$rootProject.2.2.4"

// Lifecycle components
    implementation "androidx.lifecycle:lifecycle-extensions:$rootProject.2.3.0"
    annotationProcessor "androidx.lifecycle:lifecycle-compiler:$rootProject.2.3.0"

// UI
    implementation "com.google.android.material:material:$rootProject.1.0.0"

// Testing
    androidTestImplementation "androidx.arch.core:core-testing:$rootProject.1.2.0"

}

Answer 1

我犯了一个愚蠢的错误，没有看到build.gradle(app)和build.gradle的不同之处。如果有人遇到同样的错误，请跟随this.It，我需要两天时间才能接受我的答案，但这对我来说是有效的。

build.gradle(app)

    implementation "androidx.room:room-runtime:$rootProject.roomVersion"
    annotationProcessor "androidx.room:room-compiler:$rootProject.roomVersion"
    androidTestImplementation "androidx.room:room-testing:$rootProject.roomVersion"

// Lifecycle components
   implementation "androidx.lifecycle:lifecycle extensions:$rootProject.archLifecycleVersion"
    annotationProcessor "androidx.lifecycle:lifecycle-compiler:$rootProject.archLifecycleVersion"

// UI
    implementation "com.google.android.material:material:$rootProject.materialVersion"

// Testing
    androidTestImplementation "androidx.arch.core:core-testing:$rootProject.coreTestingVersion"

保留roomVersion、archLifecycleVersion、coreTestingVersion和materialVersion的原样，并在build.gradle中添加以下版本

build.gradle

    roomVersion = '2.2.1'
    archLifecycleVersion = '2.2.0'
    coreTestingVersion = '2.1.0'
    materialVersion = '1.0.0'
}```

Answer 2

可能是因为在项目级别的build.gradle文件中缺少了对Google的maven存储库的引用：

buildscript {
    repositories {
        google() // this allow to lookup in the Google's maven repository
        jcenter()
    }

    ...
}

allprojects {
    repositories {
        google() // this allow to lookup in the Google's maven repository
        jcenter()
    }
}