我直接放出我github主要代码链接吧 下面的废话是给我自己看的 简单纪录下
整个项目代码
config.gradle全部代码
build.gradle全部代码

1.创建config.gradle 详情见github

[]就是一个map集合

//
ext {
    //生产 /开发  环境
    isRelease = true
    androidId = [
            compileSdkVersion: 29,
            buildToolsVersion: "29.0.3",
            applicationId    : "com.cw.myapplication",
            minSdkVersion    : 19,
            targetSdkVersion : 29,
            versionCode      : 1,
            versionName      : "1.0"

    ]

    appId = [
            applicationId: "com.cw.myapplication",
    ]

    //生产 测试环境
    url = [
            debug  : "http://101.2.2.2:debug",
            release: "http://101.2.2.20:release",
    ]

    appcompatLibVersion = "1.1.0"
    coreKtxLibVersion = "1.2.0"
    constraintlayoutLibVersion = "1.1.3"
    junitLibVersion = "4.12"
    extJunitLibVersion = "1.1.1"
    espressoCoreLibVersion = "3.2.0"


    dependenciesLib = [
            "appcompat"       : "androidx.appcompat:appcompat:${appcompatLibVersion}",
            "coreKtx"         : "androidx.core:core-ktx:${coreKtxLibVersion}",
            "constraintlayout": "androidx.constraintlayout:constraintlayout:${constraintlayoutLibVersion}",
            "junit"           : "junit:junit:${junitLibVersion}",
            "extJunit"        : "androidx.test.ext:junit:${extJunitLibVersion}",
            "espressoCore"    : "androidx.test.espresso:espresso-core:${espressoCoreLibVersion}"
    ]

}

2.在根目录下的build.gradle中依赖config.gradle 详情点击github

apply from: "config.gradle"
buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        jcenter()

    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.3'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

3.赋值引用 详情点击github

//赋值引用
def androidId = rootProject.ext.androidId
def appId = rootProject.ext.appId
def dependenciesLib = rootProject.ext.dependenciesLib
def url = rootProject.ext.url

具体怎么使用config.gradle里的参数 可以去github下载源码 看看

下面的代码简单说一下 我们可以通过如下代码片段 依赖指定的库

implementation dependenciesLib.appcompat

也可以通过最简洁的方式 遍历dependenciesLib集合 前面说过这个在config.gradle中定义的就是个集合 既然是集合 我们肯定可以去循环遍历他 如:

 //最简洁的方式  只需要如下代码 就依赖了全部的三方库
    dependenciesLib.each { k, v -> implementation v }

以下是全部代码

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    testImplementation dependenciesLib.junit
    androidTestImplementation dependenciesLib.extJunit
    androidTestImplementation dependenciesLib.espressoCore

    /*implementation dependenciesLib.appcompat
    implementation dependenciesLib.coreKtx
    implementation dependenciesLib.constraintlayout*/

    //最简洁的方式
    dependenciesLib.each { k, v -> implementation v }

    implementation project(":library")
}