Android Studio Build报错：Could not download support-v4.aar (com.android.support:support-v4:28.0.0)

报错信息如下：Could not download recyclerview-v7.aar (com.android.support:recyclerview-v7:28.0.0)  （这个问题搞了我一上午，太浪费时间啦！）

ERROR: Unable to resolve dependency for ':AppDemo@debugUnitTest/compileClasspath': Could not download constraint-layout-solver.jar (com.android.support.constraint:constraint-layout-solver:1.1.3)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@release/compileClasspath': Could not download support-v4.aar (com.android.support:support-v4:28.0.0)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@release/compileClasspath': Could not download design.aar (com.android.support:design:28.0.0)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@release/compileClasspath': Could not download constraint-layout.aar (com.android.support.constraint:constraint-layout:1.1.3)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@release/compileClasspath': Could not download support-media-compat.aar (com.android.support:support-media-compat:28.0.0)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@release/compileClasspath': Could not download recyclerview-v7.aar (com.android.support:recyclerview-v7:28.0.0)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@release/compileClasspath': Could not download transition.aar (com.android.support:transition:28.0.0)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@release/compileClasspath': Could not download cardview-v7.aar (com.android.support:cardview-v7:28.0.0)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@release/compileClasspath': Could not download constraint-layout-solver.jar (com.android.support.constraint:constraint-layout-solver:1.1.3)
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Affected Modules: AppDemo


ERROR: Unable to resolve dependency for ':AppDemo@releaseUnitTest/compileClasspath': Could not download support-v4.aar (com.android.support:support-v4:28.0.0)
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Affected Modules: AppDemo

原因分析：连接不上google的服务器

解决办法：1、购买VPN，*重新编译

2、找到工程级别的build.gradle文件，将

repositories {
    google()
    jcenter()
    mavenCentral()
}

修改成阿里云的服务器

allprojects {
    repositories {
        //阿里的镜像地址（注意用这个）
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
        maven { url 'http://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/jcenter' }
        //自己的工程
        maven { url 'https://maven.google.com' }
        maven { url 'https://jitpack.io' }
        jcenter()
        mavenCentral()
        maven { url "https://dl.google.com/dl/android/maven2/" }
    }
}

重新build工程。

本文地址：https://blog.csdn.net/Jason_996/article/details/111872321