无法解决android studio中的所有依赖项

Question

我收到这些错误: -

错误:无法解析':app @ debug/compileClasspath'的依赖关系:无法解析com.android.support:appcompat-v7:27.0.0.

错误:无法解析':app @ debugAndroidTest/compileClasspath'的依赖关系:无法解析com.android.support.test:runner:1.0.1.

错误:无法解析':app @ releaseUnitTest/compileClasspath'的依赖项:无法解析junit:junit:4.12.

错误:无法解析':app @ debugAndroidTest/compileClasspath'的依赖关系:无法解析com.android.support.test.espresso:espresso-core:3.0.1.

1. 我尝试了很多方法,但它并没有同步gradle.
2. 我尝试了梯度离线方法,但也没有工作.
3. 我试过添加GOOGLE MAVEN REPO REPOSITORY但是没有用.
4. 我已经尝试了这里列出的所有这些方法: - 无法解决:com.android.support:cardview-v7:26.0.0 android

同步卡住的屏幕截图

我是android studio plz的新手,省略了错误.

应用程序build.gradle文件:

    apply plugin: 'com.android.application'

android {
    compileSdkVersion 27
    buildToolsVersion "26.0.2"
    defaultConfig {
        applicationId "com.example.firstapp.myapplication"
        minSdkVersion 16
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
}

应用程序build.gradle文件

    // Top-level build file where you can add configuration options common to all sub-projects/modules.

    buildscript {

        repositories {
            google()
            jcenter()
        }
        dependencies {
            classpath 'com.android.tools.build:gradle:3.0.0'


            // NOTE: Do not place your application dependencies here; they belong
            // in the individual module build.gradle files
        }
    }

    allprojects {
    repositories {
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
}

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

Answer 1

我认为您缺少 Google Maven 存储库。

repositories {
    jcenter()
    maven {
        url "https://maven.google.com"
    }
}

您可以在此处查看完整的文档。