build.gradle

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

buildscript {
    repositories {
        jcenter()
        maven {
            url 'https://maven.google.com/'
            name 'Google'
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
        classpath 'com.jakewharton:butterknife-gradle-plugin:8.4.0'
        // 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/'
            name 'Google'
        }
        maven {url 'http://developer.huawei.com/repo/'}
    }
}

configurations.all {
    resolutionStrategy.eachDependency { DependencyResolveDetails details ->
        def requested = details.requested
        if (requested.group == 'com.android.support') {
            if (!requested.name.startsWith("multidex")) {
                details.useVersion '27.0.0'
            }
        }
    }
}

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

// 保证dex_files文件中指定的文件都加载到Main Dex中
afterEvaluate {
    tasks.matching {
        it.name.startsWith('dex')
    }.each { dx ->
        if (dx.additionalParameters == null) {
            dx.additionalParameters = []
        }
        dx.additionalParameters += '--multi-dex'
        dx.additionalParameters += "--main-dex-list=$projectDir/dex_files".toString()
    }
}